(Use for problems 1 and 2)

A simple random sample of 100 concert tickets was drawn from a normal population. The mean and standard deviation of the sample were $120 and $25, respectively.

Estimate the population mean with 90% confidence.

1. What is the LCL? (Answer to two decimal places.)

2. What is the UCL? (Answer to two decimal places.)

(Use for Problems 3 5)

A random sample of 15 hourly fees for car washers (including tips) was drawn from a normal population. The sample mean and sample standard deviation were = $14.9 and s = $6.75.

Can we infer at the 5% significance level that the mean fee for car washers (including tips) is greater than 12? In other words, perform the hypothesis test:

H₀: = 12

H₁: > 12

3. What is the critical value for the rejection region? (Answer to three decimal places.)

4. What is the test statistic? (Answer to three decimal places.)

5. Do you reject the null hypothesis, H₀? (Answer is Yes or No).