X 0

1

2

3

4

5

6

P(x)

0.03

0.11

0.28

0.37

0.09

0.07

0.05

Problem #12: Find the probability that a household has more than 4 televisions.

Scores on a university exam are normally distributed with a mean of 78 and a standard deviation of 8. the professor teaching the class declares that a score of 70 or higher is required for a grade of at least “c.” using the 68-95-99.7 rule, what percentage of students failed to earn a grade of at least “c”?