Hypothesis tests, steps of Statistical inference:

1. A restaurant chain claims that customer waiting time is of 8 minutes with a population standard deviation of 1 minute. He quality control department found in a sample of 50 clients that the average waiting time was 2.75 minutes. With the significance level of 0.05, can you conclude that the average waiting time is less than 3 minutes? Demonstrate the procedure and explain your answer.

2. Based on its experience, an insurance company calculates that the damage natural disaster in your area amounts to $35,000. After present several plans to prevent losses, the company takes a sample random sample of 200 policyholders and finds that the mean amount per claim was of $34,800, with a standard deviation of $10,300. Were they effective? prevention plans by reducing the average number of claims? Use a level of significance of 0.05.

3. The owners of a shopping center want to study shopping habits of your clients. According to previous studies, owners have the impression that a common buyer spends 0.75 hours in the center business, with a standard deviation of 0.10 hours. recently, the mall owners included some restaurants from specialties designed for customers to spend more time in it. HE hired a consulting firm to assess the effects of the restaurants. A sample of 45 clients showed that the average time spent in the mall increased to 0.80 hours.

I. Develop a hypothesis test to determine if the mean time invested in the mall is greater than 0.75 hours. use a level of significance of 0.05.

II. Suppose that the mean time to purchases actually increased from 0.75 to 0.77 hours. What is the probability that this increase will not occur? detect?

III. When the consultant informed the owners of the information in item ii, they were upset because a survey failed to detect a change