A survey asked a random sample students if they estimated they spent more or less than an hour a day on social media. Results are shown in the table below, but some values are missing. Fill in the missing values.
Social Media
More Less Total
7th grade
16
8th grade
44
Total
42 70
Social Media
More Less Total
7th grade 26 42
8th grade 16 44 60
Total 42 70 102
Note: The missing values were calculated by subtracting the given values from the row and column totals. For example, to find the missing value for "Less" in 7th grade, we subtracted 16 (the number of students who said "More" in 7th grade) from 42 (the total number of students who took the survey in 7th grade).
Use the data table below to create the given scatter plot, then fill in the guided sentence below.
x y
1 10
3 9
4 6
7 8
6 8
0 10
9 4
2 10
Click on the graph to plot a point. Click a point to delete it.
x
y
The scatter plot shows
correlation because as the plotted values of
�
x increase, the values of
�
y generally
.
The scatter plot shows a weak negative correlation because as the plotted values of x increase, the values of y generally decrease.
To fill in the missing values, we can use the information given in the table.
We know that the total number of students who estimated spending more time on social media is 42. So, we can fill in the missing value for the 7th grade students by subtracting the number of 8th grade students who estimated spending more time on social media from the total number:
Number of 7th grade students who estimated spending more time on social media = Total number of students who estimated spending more time on social media - Number of 8th grade students who estimated spending more time on social media
Number of 7th grade students who estimated spending more time on social media = 42 - 16 = 26
Now, we can fill in the missing value for the 7th grade students with 26.
Similarly, we can fill in the missing value for the 8th grade students by subtracting the number of 7th grade students who estimated spending more time on social media from the total number:
Number of 8th grade students who estimated spending more time on social media = Total number of students who estimated spending more time on social media - Number of 7th grade students who estimated spending more time on social media
Number of 8th grade students who estimated spending more time on social media = 42 - 26 = 16
Now, we can fill in the missing value for the 8th grade students with 16.
Therefore, the filled-in table would look like this:
Social Media
More Less Total
7th grade 26 ?
8th grade 16 44
Total 42 70