Question

10. Here is a list of 25 scores on a Math midterm exam: 38.5, 41.5, 52, 52.5, 61, 63, 63.5, 68, 69, 69, 78.5, 79, 80, 83, 87, 88.5, 88.5, 91, 91.5, 92, 92.5, 94, 94, 97, 97 Find P36:

Answer 1

Answer:

69

Step-by-step explanation:

Since the values in the data set has been ranked already from smallest to largest, as shown in the question.

Then calculate the index,

To find the 36th percentile using the data set,

Multiply k (36/100) by n (25) to reach an index of 9.

Then since the index is whole number,

To calculate percentile according to the 'greater than' method, count the values in the data set from smallest to largest until you reach the number ranked 9th

Which is 69.

Since the value for the 36th percentile must be greater than the first nine values, the 10th ranked value would be the kth (36th) percentile. In this data set, that value is 69.

Alternatively, using the 'greater than or equal to' method, after getting the 9th rank,

Include the ninth-ranked value, (69) in this data set.

The kth (36th) percentile is then calculated by taking the average of that value in the data set (69) and the next ranked value (69). (59 + 69) / 2 = 69.