Question

below are 36 sorted ages of acting award winner. find p25

16 18 23 24 26 27 28 28 33 34

34 35 38 39 42 46 48 48 48 49

51 51 53 55 56 58 59 62 62 63

67 67 70 71 71 77

Answer 1

As we are to calculate the 25th percentile value that is the first quartile value, we first look at the first half that is the first 18 values and the first quartile would be given as the median of those 18 values. As 18 is even number, the median is computed here as the average of the middle 2 values that is the 9^th and the 10^th value that is computed as: (Note that 33 is the 9th value here and 34 is 10th value here. )

= (33 + 34)/2

= 33.5

Therefore 33.5 is the required first quartile value here.