The test scores of 15 students are listed below.Find the lower quartile (Q1)by hand.
A)55
B)56.5
C)58
D)85
E)86

Question

The test scores of 15 students are listed below.Find the lower quartile (Q1)by hand. 
A)55 
B)56.5 
C)58 
D)85 
E)86

Quizplus · Accepted Answer

To find the lower quartile, we need to divide the data into quarters. Since we have 15 data points, the lower quartile will be the median of the first half of the data, which contains 7 points.

We first need to put the data in order from least to greatest:

54, 55, 56, 56, 57, 58, 58, 59, 62, 64, 66, 68, 72, 85, 86

The first half of this data is:

54, 55, 56, 56, 57, 58, 58

The median of this data is the average of the middle two points:

(Q1) = (56 + 57)/2 = 56.5

Therefore, the answer is B.

The Test Scores of 15 Students Are Listed Below