Let's analyze the questions based on the box-and-whisker plot.

(a) Which class had the highest test score?

• Class B had the highest test score, as its upper whisker extends further to the right, reaching a maximum close to 95, which is higher than Class A’s maximum score.

(b) Which class had a higher median test score?

• Class A has a higher median test score. The median line in Class A's box is further to the right (around 75) compared to Class B’s median (around 65).

(c) Which class had test scores with a larger interquartile range (IQR)?

• Class B has a larger IQR, as the width of its box (from Q1 to Q3) is wider than that of Class A, indicating a greater spread in the middle 50% of its scores.

(d) A score above 70 is considered passing. Which class had more passing scores?

• Class A likely had more passing scores, as a larger portion of its box (including the median) is above 70, whereas in Class B, most of the box and the median are below 70.

Would you like more detailed explanations on any of these? Here are related questions you may find interesting:

1. How can I calculate the exact interquartile range if given specific data?
2. What does the position of the median tell us about skewness in a box plot?
3. How do we interpret outliers in box plots?
4. How could we determine the number of passing scores if more data was available?
5. Why might Class A have more scores above 70 despite similar ranges?

Tip: In box-and-whisker plots, a wider box indicates a larger interquartile range (IQR), reflecting more variability in the middle 50% of data.