Question

These 20 ages of children on a school bus are in order from least to greatest. 5, 5, 5, 6, 6, 7, 7, 8, 9, 10, 10, 11, 12, 12, 12, 14, 14, 14, 15, 17
Find the

first quartile

third quartile


Find the interquartile range:

Answer 1

Answer:

the interquartile range is the Q3-Q1 where Q3 is 75th percentile and Q1 is the 25th percentile.

so the total count is 20 so 25 percentile is 25% of 20 =5 and 75th percentile is 75% of 20 = 15 and since the number are already arranged in order we just pick the 15th number-5th number   thus, our answer is

                              12-6 = 6