Question

1. Find P(Z < -1.54). Round off to 4 decimal places.

2. Find P(Z > 1.45). Round off to 4 decimal places.

3. Find P(-1.54 < Z < 1.45). Round off to 4 decimal places.

4. The monthly electric bills in a city are normally distributed with a mean of $125 and a standard deviation of $22. Find the x-value corresponding to a z-score of 1.65.

5. Find z if P(Z < z) = 0.028.

6. The weights of bags of chips for a vending machine are normally distributed with a mean of 1.34 ounces and a standard deviation of 0.18 ounce. Bags that have weights in the higher 5.7% are too heavy and will not work in the machine. What is the greatest a bag of chips can weigh and still work in the machine?

7. The average on a statistics test was 75 with a standard deviation of 15. If the test scores are normally distributed, find the probability that a student receives a test score less than 90.

8. The average on a statistics test was 75 with a standard deviation of 15. If the test scores are normally distributed, find the probability that a student receives a test score greater than 85.

9. The average on a statistics test was 75 with a standard deviation of 15. If the test scores are normally distributed, find the probability that a student receives a test score between 60 and 80.

Answer 1