Question 8.60
29.
North Carolina State University posts the grade distributions for its courses online. Students in Statistics 101 in a recent semester earned 21% As, 43% Bs, 30% Cs, 5% Ds, and 1% Fs. Here is the probability model for the grade of a randomly chosen Statistics 101 student.
| Grade | |||||
|---|---|---|---|---|---|
| Probability | 0.01 | 0.05 | 0.30 | 0.43 | 0.21 |
- Make a probability histogram for this model. Does it have the shape of a normal distribution?
- What is the probability that the student got a grade of B or better?
29.
(a) Here is the probability histogram:
The histogram does not look to be normally distributed.
(b)