1. For a given N, the interval that bounds the population mean at the 99% confidence level is ____ that which bounds the population mean at the 95% confidence level
A. equal to
B. greater than
C. less than
D. can't be determined
2. When using the t test, we reject H0 ____.
A. if tobt£ tcrit
B. if | tobt | ³ | tcrit |
C. if | tobt | £ | tcrit |
D. if tobt³ tcrit
3. A researcher believes that women today weigh less than in previous years. To investigate this belief, he randomly samples 41 adult women and records their weights. The scores have a mean of 111 lbs. and a standard deviation of 12.4. A local census taken several years ago shows the mean weight of adult women was 115 lbs.
The obtained value of the appropriate statistic for testing H0 is ____.
A. tobt = -2.07
B. tobt = +3.07
C. tobt = -1.32
D. tobt = +0.32
4. A researcher believes that women today weigh less than in previous years. To investigate this belief, he randomly samples 41 adult women and records their weights. The scores have a mean of 111 lbs. and a standard deviation of 12.4. A local census taken several years ago shows the mean weight of adult women was 115 lbs.
The df for determining tcrit = ____.
A. 41
B. 40
C. 39
D. need more information
5. If µ = 30, s = 5.2, = 28.0, s = 6.1 and N = 13, the value of the most powerful statistic to test the significance of the sample mean is ____.
A. -1.18
B. 1.96
C. 2.18
D. -1.39
6. Confidence interval is defined as ____.
A. a range of values that probably contains the population value
B. a range of values that probably contains the population mean
C. a range of values that probably contain the population standard deviation
D. a range of values that contains the population mode