Calibrations and Precision - GRE
Card 0 of 32
Michael's scale measures the mass of objects as consistently 
less than their actual mass. How would you describe the scale?
Michael's scale measures the mass of objects as consistently
Precision measures is how consistently a device records the same answer. In this case, Michael's scale is ALWAYS 
short. Even though it displays the wrong value, it is consistent. That means it is precise. Measuring a 
object will always display a mass of 
; the results are easily reproduced.
Accuracy is how well a device measures something against its accepted value. In this case, Michael's scale is not accurate because it is always off by 
.
Precision measures is how consistently a device records the same answer. In this case, Michael's scale is ALWAYS
Accuracy is how well a device measures something against its accepted value. In this case, Michael's scale is not accurate because it is always off by
Compare your answer with the correct one above
Michael buys several bags of balloons. On the package, it says that each bag has 100 balloons. He opens the bags and only one of them has 100 balloons inside; the other bags either have too many or too few.
How would you describe the bag of balloons with 100 balloons inside?
Michael buys several bags of balloons. On the package, it says that each bag has 100 balloons. He opens the bags and only one of them has 100 balloons inside; the other bags either have too many or too few.
How would you describe the bag of balloons with 100 balloons inside?
This bag is accurate because it provided the correct number of balloons, however, the process is not precise as the results were clearly not repeatable.
Accuracy deals with how close the measurement got to the accepted measurement. Precision deals with how consistent the measurement is. The bag with 100 balloons inside matched the claim made on the bag, meaning it was accurate. It was not precise because the other measurements show that the number of balloons is variable.
This bag is accurate because it provided the correct number of balloons, however, the process is not precise as the results were clearly not repeatable.
Accuracy deals with how close the measurement got to the accepted measurement. Precision deals with how consistent the measurement is. The bag with 100 balloons inside matched the claim made on the bag, meaning it was accurate. It was not precise because the other measurements show that the number of balloons is variable.
Compare your answer with the correct one above
An brand of fruit snacks claims that each bag of fruit snacks has a mass of 
. After weighing three bags, Wally observes the masses to be 
, 
, and 
.
How can Wally describe the accuracy and precision of the first bag he measured?
An brand of fruit snacks claims that each bag of fruit snacks has a mass of
How can Wally describe the accuracy and precision of the first bag he measured?
The claim for the mass of the first bag is accurate; the brand says there should be 
in each bag and there was 
in the first bag.
The claim on the first bag is not precise, as the results are not replicated universally throughout the experiment. The masses of the bags fluctuate, with the average of all three bags equal to 
.
The claim for the mass of the first bag is accurate; the brand says there should be
The claim on the first bag is not precise, as the results are not replicated universally throughout the experiment. The masses of the bags fluctuate, with the average of all three bags equal to
Compare your answer with the correct one above
A bowman is shooting arrows at a target. Which of the following demonstrates high accuracy but low precision?
A bowman is shooting arrows at a target. Which of the following demonstrates high accuracy but low precision?
Accuracy is measured as the degree of closeness to the actual measurement. In our case, accurate shots will hit the bullseye. Precision is measured as the degree of closeness of one measurement to the next. In our case, precise shots will be clustered together.
To get high accuracy but low precision, measurements must center around the target value but be variable. The bowman's arrows will not be clustered (low precision), but will be accurately distributed around the bullseye. If all the shots were averaged, the bullseye would be at the center.
Accuracy is measured as the degree of closeness to the actual measurement. In our case, accurate shots will hit the bullseye. Precision is measured as the degree of closeness of one measurement to the next. In our case, precise shots will be clustered together.
To get high accuracy but low precision, measurements must center around the target value but be variable. The bowman's arrows will not be clustered (low precision), but will be accurately distributed around the bullseye. If all the shots were averaged, the bullseye would be at the center.
Compare your answer with the correct one above
Which of these is an example of high accuracy?
Which of these is an example of high accuracy?
Accuracy is the measure of difference between a calculated value and the true value of a measurement. High accuracy demands that the experimental result be equal to the theoretical result.
In contrast, precision is a measure of reproducibility. If multiple trials produce the same result each time with minimal deviation, then the experiment has high precision. This is true even if the results are not true to the theoretical predictions; an experiment can have high precision with low accuracy.
An archer hitting a bulls-eye is an example of high accuracy, while an archer hitting the same spot on the bulls-eye three times would be an example of high precision.
Accuracy is the measure of difference between a calculated value and the true value of a measurement. High accuracy demands that the experimental result be equal to the theoretical result.
In contrast, precision is a measure of reproducibility. If multiple trials produce the same result each time with minimal deviation, then the experiment has high precision. This is true even if the results are not true to the theoretical predictions; an experiment can have high precision with low accuracy.
An archer hitting a bulls-eye is an example of high accuracy, while an archer hitting the same spot on the bulls-eye three times would be an example of high precision.
Compare your answer with the correct one above
Which of these is an example of high precision?
Which of these is an example of high precision?
Precision is a measure of reproducibility. If multiple trials produce the same result each time with minimal deviation, then the experiment has high precision. This is true even if the results are not true to the theoretical predictions; an experiment can have high precision with low accuracy.
In contrast, accuracy is the measure of difference between a calculated value and the true value of a measurement. High accuracy demands that the experimental result be equal to the theoretical result.
An archer hitting a bulls-eye is an example of high accuracy, while an archer hitting the same spot on the bulls-eye three times would be an example of high precision.
Precision is a measure of reproducibility. If multiple trials produce the same result each time with minimal deviation, then the experiment has high precision. This is true even if the results are not true to the theoretical predictions; an experiment can have high precision with low accuracy.
In contrast, accuracy is the measure of difference between a calculated value and the true value of a measurement. High accuracy demands that the experimental result be equal to the theoretical result.
An archer hitting a bulls-eye is an example of high accuracy, while an archer hitting the same spot on the bulls-eye three times would be an example of high precision.
Compare your answer with the correct one above
What is the molar concentration of a 2% by mass 
solution with a density of 
?
What is the molar concentration of a 2% by mass
By definition, 2% by mass means 2 grams of in every 100 grams of solution. In order to solve this problem, we may assume we are dealing with 100 grams of solution. We can use the density as a conversion factor to determine the volume of solution we are dealing with:
In order to calculate the number of moles of , we need to convert 2 grams of to moles using it's molecular weight. This is because we are assuming we are dealing 100 grams of a 2% solution.
In order to calculate molarity, we need to plug the moles and volumes calculated into the following equation:
By definition, 2% by mass means 2 grams of
In order to calculate the number of moles of
In order to calculate molarity, we need to plug the moles and volumes calculated into the following equation:
Compare your answer with the correct one above
Using the calibration curve given, if given the absorbance of 1.51, what would be the concentration?
Using the calibration curve given, if given the absorbance of 1.51, what would be the concentration?
A calibration curve is a graph that gives the relationship between a measured quantity and an analytical signal. In this question the analytical signal is absorbance and the measured quantity is the concentration. To answer this problem, simply determine where the absorbance value 1.5 is on the y-axis and find what point the x-axis crosses this absorbance.
A calibration curve is a graph that gives the relationship between a measured quantity and an analytical signal. In this question the analytical signal is absorbance and the measured quantity is the concentration. To answer this problem, simply determine where the absorbance value 1.5 is on the y-axis and find what point the x-axis crosses this absorbance.
Compare your answer with the correct one above
Michael's scale measures the mass of objects as consistently less than their actual mass. How would you describe the scale?
Michael's scale measures the mass of objects as consistently
Precision measures is how consistently a device records the same answer. In this case, Michael's scale is ALWAYS short. Even though it displays the wrong value, it is consistent. That means it is precise. Measuring a object will always display a mass of ; the results are easily reproduced.
Accuracy is how well a device measures something against its accepted value. In this case, Michael's scale is not accurate because it is always off by .
Precision measures is how consistently a device records the same answer. In this case, Michael's scale is ALWAYS
Accuracy is how well a device measures something against its accepted value. In this case, Michael's scale is not accurate because it is always off by
Compare your answer with the correct one above
Michael buys several bags of balloons. On the package, it says that each bag has 100 balloons. He opens the bags and only one of them has 100 balloons inside; the other bags either have too many or too few.
How would you describe the bag of balloons with 100 balloons inside?
Michael buys several bags of balloons. On the package, it says that each bag has 100 balloons. He opens the bags and only one of them has 100 balloons inside; the other bags either have too many or too few.
How would you describe the bag of balloons with 100 balloons inside?
This bag is accurate because it provided the correct number of balloons, however, the process is not precise as the results were clearly not repeatable.
Accuracy deals with how close the measurement got to the accepted measurement. Precision deals with how consistent the measurement is. The bag with 100 balloons inside matched the claim made on the bag, meaning it was accurate. It was not precise because the other measurements show that the number of balloons is variable.
This bag is accurate because it provided the correct number of balloons, however, the process is not precise as the results were clearly not repeatable.
Accuracy deals with how close the measurement got to the accepted measurement. Precision deals with how consistent the measurement is. The bag with 100 balloons inside matched the claim made on the bag, meaning it was accurate. It was not precise because the other measurements show that the number of balloons is variable.
Compare your answer with the correct one above
An brand of fruit snacks claims that each bag of fruit snacks has a mass of . After weighing three bags, Wally observes the masses to be , , and .
How can Wally describe the accuracy and precision of the first bag he measured?
An brand of fruit snacks claims that each bag of fruit snacks has a mass of
How can Wally describe the accuracy and precision of the first bag he measured?
The claim for the mass of the first bag is accurate; the brand says there should be in each bag and there was in the first bag.
The claim on the first bag is not precise, as the results are not replicated universally throughout the experiment. The masses of the bags fluctuate, with the average of all three bags equal to .
The claim for the mass of the first bag is accurate; the brand says there should be
The claim on the first bag is not precise, as the results are not replicated universally throughout the experiment. The masses of the bags fluctuate, with the average of all three bags equal to
Compare your answer with the correct one above
A bowman is shooting arrows at a target. Which of the following demonstrates high accuracy but low precision?
A bowman is shooting arrows at a target. Which of the following demonstrates high accuracy but low precision?
Accuracy is measured as the degree of closeness to the actual measurement. In our case, accurate shots will hit the bullseye. Precision is measured as the degree of closeness of one measurement to the next. In our case, precise shots will be clustered together.
To get high accuracy but low precision, measurements must center around the target value but be variable. The bowman's arrows will not be clustered (low precision), but will be accurately distributed around the bullseye. If all the shots were averaged, the bullseye would be at the center.
Accuracy is measured as the degree of closeness to the actual measurement. In our case, accurate shots will hit the bullseye. Precision is measured as the degree of closeness of one measurement to the next. In our case, precise shots will be clustered together.
To get high accuracy but low precision, measurements must center around the target value but be variable. The bowman's arrows will not be clustered (low precision), but will be accurately distributed around the bullseye. If all the shots were averaged, the bullseye would be at the center.
Compare your answer with the correct one above
Which of these is an example of high accuracy?
Which of these is an example of high accuracy?
Accuracy is the measure of difference between a calculated value and the true value of a measurement. High accuracy demands that the experimental result be equal to the theoretical result.
In contrast, precision is a measure of reproducibility. If multiple trials produce the same result each time with minimal deviation, then the experiment has high precision. This is true even if the results are not true to the theoretical predictions; an experiment can have high precision with low accuracy.
An archer hitting a bulls-eye is an example of high accuracy, while an archer hitting the same spot on the bulls-eye three times would be an example of high precision.
Accuracy is the measure of difference between a calculated value and the true value of a measurement. High accuracy demands that the experimental result be equal to the theoretical result.
In contrast, precision is a measure of reproducibility. If multiple trials produce the same result each time with minimal deviation, then the experiment has high precision. This is true even if the results are not true to the theoretical predictions; an experiment can have high precision with low accuracy.
An archer hitting a bulls-eye is an example of high accuracy, while an archer hitting the same spot on the bulls-eye three times would be an example of high precision.
Compare your answer with the correct one above
Which of these is an example of high precision?
Which of these is an example of high precision?
Precision is a measure of reproducibility. If multiple trials produce the same result each time with minimal deviation, then the experiment has high precision. This is true even if the results are not true to the theoretical predictions; an experiment can have high precision with low accuracy.
In contrast, accuracy is the measure of difference between a calculated value and the true value of a measurement. High accuracy demands that the experimental result be equal to the theoretical result.
An archer hitting a bulls-eye is an example of high accuracy, while an archer hitting the same spot on the bulls-eye three times would be an example of high precision.
Precision is a measure of reproducibility. If multiple trials produce the same result each time with minimal deviation, then the experiment has high precision. This is true even if the results are not true to the theoretical predictions; an experiment can have high precision with low accuracy.
In contrast, accuracy is the measure of difference between a calculated value and the true value of a measurement. High accuracy demands that the experimental result be equal to the theoretical result.
An archer hitting a bulls-eye is an example of high accuracy, while an archer hitting the same spot on the bulls-eye three times would be an example of high precision.
Compare your answer with the correct one above
What is the molar concentration of a 2% by mass solution with a density of ?
What is the molar concentration of a 2% by mass
By definition, 2% by mass means 2 grams of in every 100 grams of solution. In order to solve this problem, we may assume we are dealing with 100 grams of solution. We can use the density as a conversion factor to determine the volume of solution we are dealing with:
In order to calculate the number of moles of , we need to convert 2 grams of to moles using it's molecular weight. This is because we are assuming we are dealing 100 grams of a 2% solution.
In order to calculate molarity, we need to plug the moles and volumes calculated into the following equation:
By definition, 2% by mass means 2 grams of
In order to calculate the number of moles of
In order to calculate molarity, we need to plug the moles and volumes calculated into the following equation:
Compare your answer with the correct one above
Using the calibration curve given, if given the absorbance of 1.51, what would be the concentration?
Using the calibration curve given, if given the absorbance of 1.51, what would be the concentration?
A calibration curve is a graph that gives the relationship between a measured quantity and an analytical signal. In this question the analytical signal is absorbance and the measured quantity is the concentration. To answer this problem, simply determine where the absorbance value 1.5 is on the y-axis and find what point the x-axis crosses this absorbance.
A calibration curve is a graph that gives the relationship between a measured quantity and an analytical signal. In this question the analytical signal is absorbance and the measured quantity is the concentration. To answer this problem, simply determine where the absorbance value 1.5 is on the y-axis and find what point the x-axis crosses this absorbance.
Compare your answer with the correct one above
Michael's scale measures the mass of objects as consistently less than their actual mass. How would you describe the scale?
Michael's scale measures the mass of objects as consistently
Precision measures is how consistently a device records the same answer. In this case, Michael's scale is ALWAYS short. Even though it displays the wrong value, it is consistent. That means it is precise. Measuring a object will always display a mass of ; the results are easily reproduced.
Accuracy is how well a device measures something against its accepted value. In this case, Michael's scale is not accurate because it is always off by .
Precision measures is how consistently a device records the same answer. In this case, Michael's scale is ALWAYS
Accuracy is how well a device measures something against its accepted value. In this case, Michael's scale is not accurate because it is always off by
Compare your answer with the correct one above
Michael buys several bags of balloons. On the package, it says that each bag has 100 balloons. He opens the bags and only one of them has 100 balloons inside; the other bags either have too many or too few.
How would you describe the bag of balloons with 100 balloons inside?
Michael buys several bags of balloons. On the package, it says that each bag has 100 balloons. He opens the bags and only one of them has 100 balloons inside; the other bags either have too many or too few.
How would you describe the bag of balloons with 100 balloons inside?
This bag is accurate because it provided the correct number of balloons, however, the process is not precise as the results were clearly not repeatable.
Accuracy deals with how close the measurement got to the accepted measurement. Precision deals with how consistent the measurement is. The bag with 100 balloons inside matched the claim made on the bag, meaning it was accurate. It was not precise because the other measurements show that the number of balloons is variable.
This bag is accurate because it provided the correct number of balloons, however, the process is not precise as the results were clearly not repeatable.
Accuracy deals with how close the measurement got to the accepted measurement. Precision deals with how consistent the measurement is. The bag with 100 balloons inside matched the claim made on the bag, meaning it was accurate. It was not precise because the other measurements show that the number of balloons is variable.
Compare your answer with the correct one above
An brand of fruit snacks claims that each bag of fruit snacks has a mass of . After weighing three bags, Wally observes the masses to be , , and .
How can Wally describe the accuracy and precision of the first bag he measured?
An brand of fruit snacks claims that each bag of fruit snacks has a mass of
How can Wally describe the accuracy and precision of the first bag he measured?
The claim for the mass of the first bag is accurate; the brand says there should be in each bag and there was in the first bag.
The claim on the first bag is not precise, as the results are not replicated universally throughout the experiment. The masses of the bags fluctuate, with the average of all three bags equal to .
The claim for the mass of the first bag is accurate; the brand says there should be
The claim on the first bag is not precise, as the results are not replicated universally throughout the experiment. The masses of the bags fluctuate, with the average of all three bags equal to
Compare your answer with the correct one above
A bowman is shooting arrows at a target. Which of the following demonstrates high accuracy but low precision?
A bowman is shooting arrows at a target. Which of the following demonstrates high accuracy but low precision?
Accuracy is measured as the degree of closeness to the actual measurement. In our case, accurate shots will hit the bullseye. Precision is measured as the degree of closeness of one measurement to the next. In our case, precise shots will be clustered together.
To get high accuracy but low precision, measurements must center around the target value but be variable. The bowman's arrows will not be clustered (low precision), but will be accurately distributed around the bullseye. If all the shots were averaged, the bullseye would be at the center.
Accuracy is measured as the degree of closeness to the actual measurement. In our case, accurate shots will hit the bullseye. Precision is measured as the degree of closeness of one measurement to the next. In our case, precise shots will be clustered together.
To get high accuracy but low precision, measurements must center around the target value but be variable. The bowman's arrows will not be clustered (low precision), but will be accurately distributed around the bullseye. If all the shots were averaged, the bullseye would be at the center.
Compare your answer with the correct one above