E-Text 1

Student: ________________________

Number: ____________________

Group: BB1209R

Course: Res 342

Prof. René Quiñones

Date: _______

E-Test 1 (Hypothesis Test) Maximum Value (10 pts)

I Solve showing the procedure in red.

1.0 Write the null and alternative hypothesis for each of the following examples. Determine if each is a case of a two tailed, a left tailed or a right tailed test.

To test whether or not the mean price of houses in Bayamon is greater than $143,000.

〖 H〗_0: µ = 143000

H_1: µ > 143000

Right-tailed

(1 point)

To test whether the mean life of a particular brand of auto batteries is less than of 45 months.

H_0: µ = 45 months

H_1: µ < 45 months

Left-tailed

(1 point.)

2.0 If a null hypothesis is rejected with a significance level of 0.05, is it also rejected with a significance level of 0.01? Why or why not? (1 point)

3. The monthly rent for a two bedroom apartment in a particular city is reported to average $550. Suppose we want to test Ho: u= 550 versus H1: u ≠ 550. A sample of 36 two bedrooms apartment is selected. The sample means turns out to be x= $562, with a sample standard deviation of s = $40. Conduct this hypothesis test with a .05 level of significance. (2 points.)

4.0 Listed below are recorded speeds (in mi h) of randomly selected cars traveling on a section of Highway 405 in Los Angeles (based on data from Sigalert). That part of the highway has a posted speed limit of 65 mi h. Assume that the standard deviation of speeds is 5.7 mi h and use a 0.01 significance level to test the claim that the sample is from

a population with a mean that is greater than 65 mi/h.

68 68 72 73 65 74 73 72 68 65 65 73 66 71 68 74 66...