Question

Consider the following null and alternative hypotheses.
                                    Ho:  p = 0.16
                                    Ha:  p ≠
0.16
These hypotheses _______________.

		indicate a one-tailed test with a rejection area in the right tail
		indicate a one-tailed test with a rejection area in the left tail
		indicate a two-tailed test
		are established incorrectly
		are not mutually exclusive

The diameter of 3.5 inch diskettes is normally distributed. Periodically, quality control inspectors at Dallas Diskettes randomly select a sample of 16 diskettes. If the mean diameter of the diskettes is too large or too small the diskette punch is shut down for adjustment; otherwise, the punching process continues. The null hypothesis is ______.

		n ≠ 16
		n = 16
		μ = 3.5
		μ ≠ 3.5
		μ ≥ 3.5

Discrete Components, Inc. manufactures a line of electrical resistors. Presently, the carbon composition line is producing 100 ohm resistors. The population variance of these resistors "must not exceed 4" to conform to industry standards. Periodically, the quality control inspectors check for conformity by randomly select 10 resistors from the line, and calculating the sample variance. The last sample had a variance of 4.36. Assume that the population is normally distributed. Using α = 0.05, the critical value of chi-square is _________________.

		18.31
		16.92
		3.94
		3.33
		19.82

Collinsville Construction Company purchases steel rods for its projects. Based on previous tests, Claude Carter, Quality Assurance Manager, has recommended purchasing rods from Redding Rods, Inc. (population 1), rather than Stockton Steel (population 2), since Redding's rods had less variability in length. Recently, Stockton revised it rod shearing operation, and Claude has sampled the outputs from Redding's and Stockton's rod manufacturing processes. The results for Redding were s ₁² = 0.10 with n1 = 8, and, for Stockton, the results were s ₂² = 0.05 with n2 = 10. Assume that rod lengths are normally distributed in the population   If α = 0.05, the appropriate decision is ________.

		reject the null hypothesis σ12  = σ22
		reject the null hypothesis σ12 <   σ22
		do not reject the null hypothesis σ12  = σ22
		do not reject the null hypothesis σ12  <   σ22
		do nothing

Answer 1

1)

indicate a two-tailed test

2)null hypothesis is:

μ= 3.5

3_)

for 5 % level and given df critical values of X2 =

16.92

4)

do not reject the null hypothesis σ₁²  = σ₂²