Question

question #9 the plot below shows the distribution of grades for a test. if jeff earned a score of 91 on the test, in which quartile does his test score fall? a first b second c third d fourth

Explanation:

Step1: Understand quartile in box - plot

In a box - plot, the first quartile ($Q_1$) is the lower end of the box, the second quartile ($Q_2$ or median) is the line inside the box, the third quartile ($Q_3$) is the upper end of the box, and values above $Q_3$ are in the fourth quartile.

Step2: Identify quartile boundaries from the box - plot

From the given box - plot, the box ranges approximately from 75 to 90. So, $Q_1\approx75$, $Q_2$ is some value between 75 and 90, $Q_3 = 90$.

Step3: Determine Jeff's quartile

Jeff's score is 91. Since 91>90 (the value of $Q_3$), Jeff's score is in the fourth quartile.

Answer:

D. fourth