1. avionics company uses a new production method to manufacture aircraft altimeters. A single random sample of new altimeters resulted in the errors listed below. Use a 5% significance level to test the claim that the new production method has errors with a standard deviation greater than 32.2 ft, which was the standard deviation for the old production model (). If it appears that the standard deviation is greater, does the new production method appear to be better or worse than the old method? Should the company take any action?

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Find the critical X^2 statistic. Round to the nearest whole number.

3. An avionics company uses a new production method to manufacture aircraft altimeters. A single random sample of new altimeters resulted in the errors listed below. Use a 5% significance level to test the claim that the new production method has errors with a standard deviation greater than 32.2 ft, which was the standard deviation for the old production model (). If it appears that the standard deviation is greater, does the new production method appear to be better or worse than the old method? Should the company take any action?

-42 78 -22 -72 -45 15 17 51 -5 -53 -9 -109

Find the upper and lower boundaries of the 95% confidence interval for .

6. An avionics company uses a new production method to manufacture aircraft altimeters. A single random sample of new altimeters resulted in the errors listed below. Use a 5% significance level to test the claim that the new production method has errors with a standard deviation greater than 32.2 ft, which was the standard deviation for the old production model (). If it appears that the standard deviation is greater, does the new production method appear to be better or worse than the old method? Should the company take any action?

-42 78 -22 -72 -45 15 17 51 -5 -53 -9 -109

Compute the test statistic. Round to the nearest whole number.

8. An independent testing agency was hired prior to the November 2010 election to study whether or not the work output is different for construction workers employed by the state and receiving prevailing wages versus construction workers in the private sector who are paid rates determined by the free market. A sample of 125 private sector workers reveals an average output of 74.3 parts per hour with a sample standard deviation of 16 parts per hour. A sample of 125 state workers reveals an average output of 69.7 parts per hour with a sample standard deviation of 18 parts per hour.

What is the achieved level of significance in your hypothesis test? Round to 3 decimal points, e.g. 0.XXX.

In developing your answer, you may assume that the unknown variances are equal.