sample mean

The mean amount purchased by each customer at Churchill's Grocery Store is $22 with a standard deviation of $7. The population is positively skewed. For a sample of 50 customers, answer the following questions: a. What is the likelihood the sample mean is at least $23? (Round the z-value to 2 decimal places and the final answer to 4 decimal places.) Sample mean b. What is the likelihood the sample mean is greater than $20 but less than $23? (Round the z-value to 2 decimal places and the final answer to 4 decimal places.) Sample mean c. Within what limits will 95% of the sample means occur? (Round the final answers to 2 decimal places.) Sample mean and