Probability based on Normal Distribution
The mean amount purchased by a typical customer at Churchill's Grocery Store is $23.50 with a standard deviation of $5.00. Suppose the distribution of amounts purchased follows the normal distribution. For a sample of 50 customers, answer the following problems.
1. a. What is the probability the sample mean is at least $25.00?
2. b. What is the probability the sample mean is greater than $22.50 but less than $25.00?
3. c. Within what limits will 90 percent of the sample means occur?