Question

what is the difference between the number of students who did more than 36 sit - ups and the number of students who did fewer than 25 sit - ups?
a 1
b 11
c 6
d 18

Explanation:

Step1: Count the number of students who did more than 36 sit - ups

Looking at the stem - and - leaf plot, the numbers for students who did more than 36 sit - ups:
For the row with stem 4: there are 3 numbers (46, 47, 47)
For the row with stem 5: there are 3 numbers (50, 53, 52)
For the row with stem 6: there is 1 number (66)
For the row with stem 7: there are 2 numbers (72, 70)
For the row with stem 8: there are 0 numbers
For the row with stem 9: there are 0 numbers
The total number of students who did more than 36 sit - ups is \(3 + 3+1 + 2=9\)

Step2: Count the number of students who did fewer than 25 sit - ups

Looking at the stem - and - leaf plot, for the row with stem 1: there are 0 numbers
For the row with stem 2: there are 0 numbers (since we want fewer than 25, and the numbers in the stem 2 row are 20, 22, 26. 20 and 22 are less than 25)
The number of students who did fewer than 25 sit - ups is 2

Step3: Calculate the difference

The difference is \(9 - 2=7\)

Answer:

C. 6