A scatterplot is a diagram that shows the values of two variables and provides a general illustration of the relationship between them.

The data points follow an overall linear trend, as opposed to being randomly distributed. Though there are a few outliers, there is a general relationship between the two variables.

A line could accurately predict the trend of the data points, suggesting there is a linear correlation. Since the y-values decrease as the x-values increase, the correlation must be negative. We can see that a line connecting the upper-most and lower-most points would have a negative slope.

An exponential relationship would be curved, rather than straight.

The first graph is random scatter, no correlation, the second is perfect linear, corellation , the last two have fairly strong positive and negative corellations, the student should know that a corellation of  is much weaker than them

To find the range, subtract the minimum value from the maximum value

minimum: 

maximum: 

So,

maximum - minimum = 

The median is the middle value of the set in increasing order.

In this set of 11 entries, the median is the 6th entry of the set in increasing order, or 26.

The number of entries is the number of digits on the right hand side of the column.

Since there are 21 total digits, there are 21 total entris that make up the stem and leaf plot.

This stemplot is read as follows: the stem is the tens digit and each digit in the "leaves" section is a ones digit. Put them together to have a data point.

53, 65, 68, 69, 70, 72, 72, 79, 83, 84, 85, 87, 89, 90, 94

In the particular case there are 15 data points therefore the median is 79. Thus the first quartile is 69 and the third quartile is 87.

Finding the interquartile range is subtracting the first quartile from the 3rd quartile.

You can see from the histogram that the two most frequent ranges for values are 62-64 and 64-66, with 5 values in each group. And from the answer choices, you should see that only one choice, 62-68, contains both of the high-frequency bars.  It also contains the next-highest bar (66-68, with a total of 4), so at 14 total values the range 62-68 has the highest frequency of any of these six-inch-range sets in the choices.

For skewed distributions, the outliers can greatly affect the value of the mean and the standard deviation. Therefore, the median and IQR would be better measures of center and spread because they are not greatly influenced by outlier values.

Entering the data into a calculator you can quickly find the mean to be 6.5 and the sd to be 1.6 6.5-3.2=3.3 3.3>2 so iv is false and by virtue of this 2 is an outlier so i is true.

Between ii and iii, the data is not bell shaped, and does exhibit a slight right skew without the mentioned pt due to more density on 5 and 6 hours than 8 and 9