In testing the hypothesis H0:  μ = 800 vs.Ha:  μ ≠800. A sample of size 40 is chosen.the sample mean was found to be 812.5 with a standard deviation of25, then the of the test statistic is:
| | Z=0.0401 |
| | Z=-3.16 |
| | Z=3.16 |
| | Z=12.5 |
In a sample of 500 voters, 400indicated they favor the incumbent governor.  The 95%confidence
interval of votersnot favoring the incumbent is
| | 0.782 to 0.818 |
| | 0.120 to 0.280 |
| | 0.765 to 0.835 |
| | 0.165 to 0.235 |
A Type II error is committed if we make:
| | a correct decision when the null hypothesis is false |
| | correct decision when the null hypothesis is true |
| | incorrect decision when the null hypothesis is false |
| | incorrect decision when the null hypothesis is true |
What is the value of z α/2 for an 85% confidenceinterval?
A random sample of size 15 taken from a normally distributedpopulation revealed a sample mean of 75 and a sample variance of25. The upper limit of a 95% confidence interval for the populationmean would equal:
