SAT Math - Mean | Practice Hub

Determine the mean:

Explanation

The mean is the average of all numbers in the data set.

Add the numbers, and divide the total sum by four, since there are four numbers.

$\frac{13+5+8+(-6)}{4} = \frac{20}{4} =5$

The answer is:

Find the mode of the data set.

Explanation

The mode of a data set is the data point(s) that appear the most often.

In the data set for this problem, both 4 and 5 appear twice, and no other number appears more than twice.

$({2,9,{\color{Blue} 4},{\color{Green} 5},8,3,{\color{Green} 5},{\color{Blue} 4}})$

So for this data set there are two modes, 4 and 5.

Stem_and_leaf

Above is the stem-and-leaf display for a group of test scores. Order the mean, the median, and the mode of the scores from least to greatest.

Mean, median, mode

Mean, mode, median

Mode, median, mean

Median, mean, mode

Median, mode, mean

Explanation

The scores represented can be found from matching the tens digits in the "stem" to the units digits that form the "leaves" in their row. For example, the "leaves" in the "5" row are "2 2 4 4 7 7 8", so the scores will be 52, 52, 54, 54, 57, 57, and 58.

There are 53 scores represented, so to find the median, look for the middle score, in position

$\frac{53+1}{2} = 27$ .

As can be seen in this diagram, the score - the median - is 74.

Stem_and_leaf_1

The most frequently occurring "leaf" is the "6" in the "7" row, so the mode is 76.

The mean is the sum of the scores divided by 53. If we add the scores, we get

$\sum x = 3,763$ , the mean is

$\frac{\sum x }{n}=\frac{ 3,763}{53} = 71$

In ascending order, the values are mean, median, mode.

What is the mean of: ?

$61.\overline{33}$

Explanation

Step 1: Find the sum of the values...

Step 2: Find how many numbers are given...

There are numbers.

Step 3: To find the mean, divide the sum by how many numbers....

$\frac {368}{6}=61.\overline{33}$

Find the mean of the following numbers:

Explanation

The mean is the average of all the number in the data set.

$\frac{14+8+23+51}{4} = \frac{96}{4}$

The answer is:

Find the mean of the following set:

Explanation

Another word for mean is average. To find the average of this set of numbers, add them up, then divide by the amount of numbers in the set. In this case there are 5 numbers in the set, meaning we will divide our answer by 5.

$\frac{6+91+12+31+12}{5}=\frac{152}{5}=30.4$

Karen wants to get an average of 92% at the end of the semester in her class. She has 1 test left to take before the semester is over to raise her average. If she recieved an 88%, 87%, 95%, and 93% on her tests what does she need to recieve on her last test to obtain the 92% average?

97%

93%

100%

95%