11

1. A sample of 25 cereal boxes yield a mean weight of 1.02 pounds. Assume weight is normally distributed and population standard deviation is 0.03 pounds.The 95% confidence interval for mean weight is
2. a.-1.008 to 1.008
3. b.-1.032 to 1.032
4. c.1.008 to 1.032
5. d.none of the above

1.25 points

QUESTION 12

1. A 99% confidence interval
2. a.shows that you are 99% confident that the population mean lies within the interval
3. b.means that there is a 1% chance that the population mean falls outside the interval
4. c.shows that you are 99% confident that sample mean lies within the interval
5. d.both a and b

1.25 points

QUESTION 13

1. A sample of 50 virginians show an average income of $45000.
2. a.The point estimate for mean age is $45000
3. b.The point estimate can not be calculated as standard deviation is known
4. c.The point estimate can not be calculated as confidence level is not given
5. d.none of the above

1.25 points

QUESTION 14

1. To construct the confidence interval the t-distribution is to be used when
2. a.population standard deviation is known
3. b.only when sample size is small
4. c.both a and b
5. d.none of the above

1.25 points

QUESTION 15

1. The t value to be used to construct a 90% confidence interval witn n=28 is
2. a.1.703
3. b.2.052
4. c.depends on syandard deviation
5. d.none of the above

1.25 points

QUESTION 16

1. A consumer research group wants to test the claim that a new car will travel at least 25 milesper gallon.
2. a.In hypothesis testing,the null hypothesis is population mean is less or equal to 25
3. b.In hypothesis testing,the alternatehypothesis is population mean is less or equal to 25
4. c.In hypothesis testing,the null hypothesis is population mean is greater or equal to 25
5. d.none of the above

1.25 points

QUESTION 17

1. A consumer research group wants to test the claim that a new car will travel at least 25 miles per gallon.Assume sample size = 35 and a population standard deviation of 6 and a sample mean of 23.Testthe hypothesis at 1% level of significance.
3. a.Your conclusion would be 'reject Ho'
4. b.Your conclusion would be 'reject Ha'
5. c.Notenough information is given to draw a conclusion
6. d.none of the above

1.25 points

QUESTION 18

1. Test the following hypothesis
2. H_o:= 16
3. Ha_: 16
5. n=40, s= 8, X = 19, = .05
7. a.Use z distribution
8. b.Reject Ho
9. c.use degree of freedom = 41
10. d.noneof the above

1.25 points

QUESTION 19

1. Assume x is normally distributed.A sample of 25 yields a mean of 96.52 and a sample statndard deviation of 10.70.The 90% confidence interval is approximstely
2. a.90.86 - 102.18
3. b.92.86 - 102.18
4. c.90.86 - 100.18
5. d.none of the above