Question

you were given the following box plot that represents the number of books each student read last year. what percentage of students read 9 or more books?
number of books read
box plot with number line from 0 to 20, box from around 9 to 14, median line at 11, whiskers from 7 to 18, and options a: 0%, b: 25%, c: 50%, d: 75%

Explanation:

Step1: Recall Box Plot Percentiles

In a box plot, the box represents the interquartile range (IQR), with the median (50th percentile) inside. The data is divided into four quartiles: 25% below the first quartile (Q1), 25% between Q1 and median, 25% between median and third quartile (Q3), and 25% above Q3.

Step2: Analyze the Box Plot

Looking at the box plot for "Number of Books Read", the median line (middle of the box) is at 11 (or around), but more importantly, the lower edge of the box (Q1) seems to be at 9? Wait, no—wait, the box starts where? Wait, the plot: the whisker starts at 7 (the top dot) and the box starts, then the median, then the box ends, then the lower whisker to 18. Wait, no, actually, in a box plot, the box spans from Q1 (25th percentile) to Q3 (75th percentile), and the median is inside. Wait, no—wait, the key is: the data below the median is 50%, above is 50%? No, quartiles: Q1 is 25th, median 50th, Q3 75th. So the area above Q1? Wait, no, the question is "9 or more books". Let's see: the box plot—if the lower quartile (Q1) is at 9, then the percentage of data ≥9 would be 100% - 25% = 75%? Wait, no. Wait, let's think again.

Wait, the box plot: the left side of the box is Q1 (25th percentile), median (50th) in the middle, right side Q3 (75th). So data below Q1: 25%, between Q1 and median: 25%, between median and Q3: 25%, above Q3: 25%. Wait, no—total data: 100%. So from Q1 to max: 75% (since Q1 is 25th, so above Q1 is 75%). Wait, if the Q1 (25th percentile) is at 9, then all data from 9 to max is 75% (because 100% - 25% = 75%). So the percentage of students who read 9 or more books is 75%.

Answer:

75% (Option D: 75%)