Question

the stem and leaf plot shows the numbers of sit - ups a group of students did in p.e. what is the difference between the number of students who did more than 36 sit - ups and the number of student did fewer than 25 sit - ups? a 18 b 1 c 11 d 6

Explanation:

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

For numbers more than 36:

• In stem 3: leaves \(7\) (i.e., \(37\))
• In stem 4: \(4,6,7,7\) (i.e., \(44,46,47,47\))
• In stem 5: \(0,3\) (i.e., \(50,53\))
• In stem 6: \(2,2\) (i.e., \(62,62\))
• In stem 7: \(6\) (i.e., \(76\))
• In stem 9: \(0,2\) (i.e., \(90,92\))

The number of leaves is \(1 + 4+2 + 2+1+2=12\)

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

For numbers fewer than 25:

• In stem 0: \(9\) (i.e., \(9\))
• In stem 1: \(3,7,9\) (i.e., \(13,17,19\))
• In stem 2: \(0,3\) (i.e., \(20,23\))

The number of leaves is \(1+3 + 2=6\)

Step3: Calculate the difference

The difference is \(12-6 = 6\)

Answer:

D. 6