1. A marketing firm opens a small booth at a local mall over the weekend, where shoppers are asked how much money they spent at the food court. The objective is to determine the average monthly expenditures of shoppers at the food court. Has the marketing firm committed any sampling bias? Explain your answer.
2. When a pizza restaurant's delivery process is operating effectively, pizzas are delivered in an average of 45 minutes with a standard deviation of 6 minutes. To monitor its delivery process, the restaurant randomly selects five pizzas each night and records their delivery times. Assume that the population of all delivery times on a given evening is normally distributed with a mean of= 45 minutes and a standard deviation of= 6 minutes

a. Explain why we are able to utilize such a small sample size.

b.Suppose that the mean of the five sampled delivery times on a particular evening is= 55 minutes. What would you conclude about whether the restaurant's delivery process is operating effectively? Why?

3. On January of this year, a surveying organization released the results of a poll concerning American attitudes toward the 2021 Olympic games in Japan. The poll results were based on telephone interviews with a randomly selected national sample of 1,011 adults.

a.Suppose we wish to use the poll's results to justify the claim that more than 30 percent of American adults say that track and field is their favorite Olympic event. The poll actually found that 32 percent of respondents reported that track and field was their favorite event. If we assume that 30 percent of Americans adults say track and field is their favorite event, calculate the probability of observing a sample proportion of .32 or more.

b.Based on the probability you computed in part a, would you conclude that more than 30 percent of American adults say that track and field is their favorite Olympic event?