a) A manager at the Kemboja Car Sales and Services Enterprise wishes to estimate the number...

a) A manager at the Kemboja Car Sales and Services Enterprise wishes to estimate the number of days it takes for his car dealer to sell a local made car model. A random sample of 50 cars was selected and the mean number of days his car dealer is able to sell a local made car is 50 days. Assume the population standard deviation is 6 days.

i) Find the best point estimate of the population mean. Find the standard error of the

mean.

ii) Calculate the 99% confidence interval of the population mean number of days a car

dealer is able to sell a local made car.

b) As an aid for improving students’ study habit, 6 students were randomly selected to attend a seminar on the importance of education in life. The table shows the number of hours each student studied per week before and after the seminar. At the 95% confidence interval, did attending seminar increase the mean number of hours the students studied per week?

Before 12 15 18 10 13 5 After 17 20 21 15 22 7

Given Σd = - 29; Σd2 = 169

Expert Solution

orchestra answered 1 year ago

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