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MAT 155 Lab 7

Sections 8.1-4 Hypothesis Testing – Part 1

Date: ______Student’s Name______Score______

Lab7Hypothesis-1.doc

Team #_____ Section______

1. Use Statdisk to generate the output shown in the graphic below. Complete the following information. The hypothesis test is for mean, proportion, or standard deviation: ______; H0: ______H1: ______

Critical value is t or z: _____ = ______; p-value is ______

2. Use the given claim and test statistic to find the p-value. Claim: The mean height of women is at least 63.5 inches. Test statistic (computed z-value): z = -2.17. Draw and label sketch, show your work, and circle your answer.

(1) Use TI calculator; (2) Use StatDisk; (3) Use Table A-2; (4) Use Excel program


3. In a study of store checkout-scanners, 1234 items were checked and 20 of them were found to be overcharges. Use a 0.05 significance level to test the claim that 1% of sales scanned are overcharges. (Before scanners were used, the overcharge rate was estimated to be about 1%.) Use the 5-Step Form. Round to 3-decimal places.

4. When people smoke, the nicotine they absorb is converted to cotinine, which can be measured. A sample of 40 smokers has a mean cotinine level of 172.5. Assuming that σ is known to be 119.5, use a 0.01 significance level to test the claim that the mean cotinine level of all smokers is less than 200.0. Use the 5-Step Form.

5. State the decision rule to test the null hypothesis. Out of 178 observations, 59% were successes. Show work to justify your choice of answer. H0: p = 0.58. Confidence level: 98%.

(a) Reject H0 if < 1.96.

(b) Reject H0 if > 2.33 or < -2.33.

(c) Reject H0 if > -313.355.

(d) Reject H0 if > 2.33 or < -2.33.

6. The world’s smallest mammal is the bumblebee bat, also known as the Kitti’s hog-nosed bat (or Craseonycteris thonglongyai). Such bats are roughly the size of a large bumblebee. Listed below are weights (in grams) from a sample of these bats. Assuming that the weights of all such bats have a standard deviation of 0.30 g, use a 0.05 significance level to test the claim that these bats are from the same population with a known mean of 1.8 g. Do the Bats appear to come from the same population? Show appropriate work to justify your answers.

1.7 / 1.6 / 1.5 / 2.0 / 2.3 / 1.6 / 1.6 / 1.8 / 1.5 / 1.7 / 2.2 / 1.4 / 1.6 / 1.6 / 1.6

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