Question

How many in a car? A study of rush-hour traffic in San Francisco counts the number of people in each car entering a freeway at a suburban interchange. Suppose that the number of people per car in the population of all cars that enter at this interchange during rush hours has a mean of μ = 1.7 and a standard deviation of σ = 0.85.

a.Describe the shape of the sampling distribution of x ̅ for SRSs of size n = 125 from the population of all cars that enter this interchange during rush hours. Justify your answer.

b.What is the probability that the mean number of people in a random sample of 125 cars that enter at this interchange during rush hours is at least 1.9? (Fill in the blanks)

µ_x-bar = _____________

σ_x-bar = _____________

Shape: ____________________________________________________________

P(x-bar ________)

z-score = ______________________

P(x-bar __________) = ________________________________________

Answer 1