Question

to be considered for pilot school, 12 students took a spatial reasoning test that resulted in this list of scores. find the value of the 90th percentile.
152 121 130 143 122 101 137 98 138 127 145 117
(1 point)
○ 101
○ 145
○ 143
○ 11

Explanation:

Step1: Sort the data

Sort the scores in ascending order: \(98, 101, 117, 121, 122, 127, 130, 137, 138, 143, 145, 152\)

Step2: Calculate the index

Use the formula \(i=\frac{p}{100}\times n\), where \(p = 90\) (the percentile) and \(n=12\) (the number of data points). Then \(i=\frac{90}{100}\times12 = 10.8\)

Step3: Determine the value

Since \(i\) is not an integer, round up to the next integer. So we take the \(11^{th}\) value in the sorted list.

Answer:

\(145\)