Assuming the true proportion is 15%, what is the approximate probability that more than 10% of the sample would report that they experienced extreme levels of stress during the past month?

Suppose that you are studying the number of vehicles owned by a US household. You find that the average is 1.9 vehicles per household with a standard deviation of 2.8 vehicles per household. What is the most likely shape for the population described above?  Find the probability that 40 randomly selected households have an AVERAGE number of vehicles greater than 2.5.

The patient recovery time from a particular surgical procedure is normally distributed with a mean of 5.3 days and standard deviation of 1.1 days. Use your graphing calculator to answer the following questions. Write your answers in percent form. Round your answers to the nearest tenth of a percent.a) What is the probability of spending less than 8 days in recovery? %b) What is the probability of spending more than 5 days in recovery? %c) What is the probability of spending between 5 days and 8 days in recovery? %

Suppose that the monthly charges for cell phone plans in the United States are normally distributed with a mean of $93 and a standard deviation of $19. What is the probability that any one cell phone user has a monthly plan that exceeds $76? Round your answer to at least three decimal places.

Suppose the manager agrees to pay each employee a $50 bonus if they meet a certain goal. On a typical Saturday, the oil change facility will perform 40 oil changes between 10 AM and 12PM. Treating this as a random sample, there would be a 10% chance of the mean oil change time being at or below what value.

Cody took his first physics exam and scored an 80. The population mean for this exam is 70, and the standard deviation is 5. What is the probability of selecting a person with a score greater than Cody’s?

For a normally distributed population with a mean of 35 and a standard deviation of 7.5, if a sample of 40 is taken from the population, what is the probability that the sample mean will be greater than 37.5?