Answer:
a. negatively skewed
b. positively skewed
c. bimodal
Step-by-step explanation:
a. If the exam is quite easy, it is expected that the majority of the students score well on the test, and since most of the data is in closer to the maximum value rather than the minimum, the histogram has negatively skewed shape.
b. If the exam is quite hard, it is expected that the majority of the students score poorly on the test, and since most of the data is in closer to the minimum value rather than the maximum, the histogram has positively skewed shape.
c. If half of the students are expected to do well and half are expected to do poorly, it is fair to assume a near bell-shaped distribution, which results in a bimodal histogram.