STATS 211 FINAL
EXAM
1. A gasoline tank’s capacity is Normal with mean 15.0 gallons, standard deviation 0.15
gallons. The manufacturer considers the largest 2% of tanks too large. How large must a
tank be to be too large?
a) 15.20 gallons
b) 15.31 gallons ✅
c) 14.80 gallons
d) 15.45 gallons
2. With the same distribution (mean 15, sd 0.15), what proportion of tanks will hold
between 14.75 and 15.10 gallons?
a) ~50%
b) ~70% ✅
c) ~30%
d) ~90%
3. If a simple random sample of 4 tanks is selected (independent), what is the probability
that all four hold between 14.75 and 15.10 gallons?
a) (0.70)^2
b) (0.70)^4 ✅
c) ~50%
d) ~100%
4. If four tanks are randomly selected, what is the probability that their average capacity
will be between 14.75 and 15.10 gallons?
a) ~50%
b) ~70%
c) ~90% ✅
d) ~30%
,5. The p-value based on a two-sided alternative hypothesis will always be ______ the
p-value based on a one-sided alternative hypothesis of the same data.
a) Equal to
b) Larger than ✅
c) Smaller than
d) Unrelated to
6. The smaller the p-value, the stronger the evidence ______ the null hypothesis provided
by the data.
a) For
b) Against ✅
c) Irrelevant to
d) Conditional on
7. If a study finds statistical significance, then practical significance will also necessarily be
found.
a) True
b) False ✅
8. Very large sample sizes will allow very small effects to become statistically significant.
a) True ✅
b) False
9. When the sample is very large, the corresponding t distribution is ______ the normal
distribution.
a) Farther from
b) Very similar to / close to ✅
c) Always above
d) Completely different
10. The margin of error includes the effects of sampling variability, nonresponse bias, and all
other sources of error possible in a study.
a) True
b) False ✅
, 11. The margin of error for a confidence interval for the mean increases as the sample size
increases.
a) True
b) False ✅
12. The margin of error for a confidence interval for the mean based on sample size nnn
increases as the confidence level decreases.
a) True
b) False ✅
13. The margin of error for a confidence interval decreases as the population standard
deviation decreases.
a) True ✅
b) False
14. The sample size required to obtain a confidence interval with specified margin of error
mmm increases as the confidence level increases.
a) True ✅
b) False
15. The margin of error in a confidence interval captures errors present from ______ only.
a) Non-response bias
b) Random sampling only ✅
c) Measurement error
d) Entirely from the data collection method
16. Confidence intervals are resistant to outliers in the data set.
a) True
b) False ✅
17. Score-S-Up claims its study program increases ACT scores by 4 points on average. The
consumer group wants to test if the actual mean increase differs from 4. What are the
hypotheses?
a) H0:μ=4,Ha:μ≠4H_0: \mu = 4,\quad H_a: \mu \neq 4H0:μ=4,Ha:μ=4 ✅
EXAM
1. A gasoline tank’s capacity is Normal with mean 15.0 gallons, standard deviation 0.15
gallons. The manufacturer considers the largest 2% of tanks too large. How large must a
tank be to be too large?
a) 15.20 gallons
b) 15.31 gallons ✅
c) 14.80 gallons
d) 15.45 gallons
2. With the same distribution (mean 15, sd 0.15), what proportion of tanks will hold
between 14.75 and 15.10 gallons?
a) ~50%
b) ~70% ✅
c) ~30%
d) ~90%
3. If a simple random sample of 4 tanks is selected (independent), what is the probability
that all four hold between 14.75 and 15.10 gallons?
a) (0.70)^2
b) (0.70)^4 ✅
c) ~50%
d) ~100%
4. If four tanks are randomly selected, what is the probability that their average capacity
will be between 14.75 and 15.10 gallons?
a) ~50%
b) ~70%
c) ~90% ✅
d) ~30%
,5. The p-value based on a two-sided alternative hypothesis will always be ______ the
p-value based on a one-sided alternative hypothesis of the same data.
a) Equal to
b) Larger than ✅
c) Smaller than
d) Unrelated to
6. The smaller the p-value, the stronger the evidence ______ the null hypothesis provided
by the data.
a) For
b) Against ✅
c) Irrelevant to
d) Conditional on
7. If a study finds statistical significance, then practical significance will also necessarily be
found.
a) True
b) False ✅
8. Very large sample sizes will allow very small effects to become statistically significant.
a) True ✅
b) False
9. When the sample is very large, the corresponding t distribution is ______ the normal
distribution.
a) Farther from
b) Very similar to / close to ✅
c) Always above
d) Completely different
10. The margin of error includes the effects of sampling variability, nonresponse bias, and all
other sources of error possible in a study.
a) True
b) False ✅
, 11. The margin of error for a confidence interval for the mean increases as the sample size
increases.
a) True
b) False ✅
12. The margin of error for a confidence interval for the mean based on sample size nnn
increases as the confidence level decreases.
a) True
b) False ✅
13. The margin of error for a confidence interval decreases as the population standard
deviation decreases.
a) True ✅
b) False
14. The sample size required to obtain a confidence interval with specified margin of error
mmm increases as the confidence level increases.
a) True ✅
b) False
15. The margin of error in a confidence interval captures errors present from ______ only.
a) Non-response bias
b) Random sampling only ✅
c) Measurement error
d) Entirely from the data collection method
16. Confidence intervals are resistant to outliers in the data set.
a) True
b) False ✅
17. Score-S-Up claims its study program increases ACT scores by 4 points on average. The
consumer group wants to test if the actual mean increase differs from 4. What are the
hypotheses?
a) H0:μ=4,Ha:μ≠4H_0: \mu = 4,\quad H_a: \mu \neq 4H0:μ=4,Ha:μ=4 ✅
