Hello , below there are 3 questions that I need lots of help on. Please make sure to explain everything thoroughly using clear explanations, as well as proper formulas and calculations because I am very confused.

Question 1 - The Baily Hill Bicycle Shop sells mountain bikes and offers a maintenance program. The manager has found the average repair bill during the maintenance program's first year to be $15.30 with a standard deviation of $7.00.

a. What is the probability a random sample of 40 customers will have a repair cost exceeding $16.00?

b. What is the probability the mean repair cost for a sample of 100 customers will be between $15.10 and $15.80?

c. The manager has decided to offer a Spring Special. He is aware of the mean and the standard deviation for repair bills last year. Therefore, he has decided to randomly select and repair the first 50 bicycles for $14.000 each. He notes this is not even 1 standard deviation below the mean price to make such repairs. He asks your advice. Is this a risky thing to do? Based upon the probability of a repair bill being $14.00 or less, what would you recommend? Discuss.

Question 2 - In a study conducted by American Express, corporate clients were surveyed to determine the extent to which hotel room rates quoted by central reservation systems differ from the rates negotiated by the companies. The study found that the mean overcharge by hotels was $11.35 per night. Suppose a follow-up study was done in which a random sample of 30 corporate hotel bookings was analyzed. Only those cases where an error occurred were included in the study. The following data show the amounts by which the quoted rate differs from the negotiated rate. Positive values indicate an overcharge and negative values indicate an undercharge.

$15.45	$24.81	$6.02	$14.00	$25.60	$8.29
-$17.34	-$5.72	$11.61	$3.48	$18.91	$7.14
$6.64	$12.48	$6.31	-$4.85	$5.72	$12.72
$5.23	$4.57	$15.84	$2.09	-$4.56	$3.00
$23.60	$30.86	$9.25	$0.93	$20.73	$12.45

a. Compute a 95% confidence interval estimate for the mean error in hotel charges. Interpret the confidence interval estimate.

b. Based on the interval computed in apart a, do these sample data tend to support the results of the America Express study? Explain.

Question 3 - A recent article in The Wall Street Journal entitled "As Identity Theft Moves Online, Crime Rings Mimic Big Business" states that 39% of the consumer scam complaints by American consumers are about identity theft. Suppose a random sample of 90 complaints is obtained. Of these complaints, 40 were regarding identity theft. Based on these sample data, what conclusion should be reached about the statement made in the Wall Street Journal? (Test usinga = 0.10).