Question

6. Assume that the weights of coins are normally distributed with a mean of 5.67 g and a standard deviation 0.070 g. A vending machine will only accept coins weighing between 5.48 g and 5.82 g. What percentage of legal quarters will be rejected by the machine? Give your answer in the percentage format (using % symbol), rounded to two decimal places.

7. Assume that values of variable x are normally distributed, with the mean μ = 16.2 and the standard deviation σ = 1.9. Find the probability that x is greater than 14.1. Round your answer to four decimal places.

8. Use the standard normal distribution to find the indicated probability. Find P(−1.10 < z < −0.36). Round your answer to four decimal places.

9. Central Limit Theorem. Car repair bills are normally distributed with a mean of 270 dollars and a standard deviation of 20 dollars. If 64 of these repair bills are randomly selected, find the probability that they have an average cost of more than 276 dollars. Show your answer in the percentage form (using % symbol), rounded to two decimal places.

Answer 1