Suppose that over the past 30 years during any given week of the major-league season, an average of µ = 12 players are hit by wild pitches. Assume that the distribution is normal with a standard deviation of σ =3. For a sample of n = 4 weeks, in which the daily temperature was extremely hot, the weekly average of hit-by- pitch players was M = 16. Are players more likely to get hit by pitches during hot weeks? Use a one-tailed test with α = .01. Report the results in APA

Mileage data of new model cars follow a normal distribution with an average mileage of 26 mpg and a standard deviation of 7. Consider a sample of size 15 cars. What is the probability that the mean mileage of these selected cars is at most 27.5 mpg?

A pizza delivery chain advertises that it will deliver your pizza in 35 minutes from when the order is placed. Being a skeptic, you decide to test and see if the mean delivery time is actually more than 35 minutes. For the simple random sample of 14 customers who record the amount of time it takes for each of their pizzas to be delivered, the mean is 37.0 minutes with a standard deviation of 9.9 minutes. Assume that the population distribution is approximately normal. Perform a hypothesis test using a 0.05 level of significance. Step 1 of 3: State the null and alternative hypotheses for the test. Fill in the blank below. Ho: 35 Họ 1 = H₂H = 35

Boxes of cereal produced in a given factory are regularly inspected and must contain an average weight of 500 grams. The individual box weights are assumed to follow a normal distribution with a mean of 500 and a standard deviation of 20 grams. In routine inspections, the inspector selects a random sample of 14 cereal boxes and if the average sample weight is below 495 or above 505, the manufacturing process is stopped and the box filling machine is adjusted. a. Suppose a change occurs in the machine changing the average weight from 500 to 493 grams, without changing the standard deviation. What would be the proportion of sample mean weights outside the limits [495, 505]; remembering that proportion is a number between 0 and 1?