COHP 350 Final Exam Review
Questions with Accurate Answers
A 95 percent confidence interval is that range of values around a sample mean
that has a 0.95 probability of containing the true population mean. correct
answer True
A biologist has taken a random sample of a specific type of fish from a large lake
to check for levels of mercury. A 95 percent confidence interval was calculated to
be 6.8 ± 1.2 pounds. Re-read the definition of a confidence interval then choose
which of the following is true. correct answer In repeated sampling, 95 percent of
the time the true population mean of the weight of the fish will be included in this
confidence interval
A cardiologist claims the probability that a cardiac unit patient, picked at random,
has hypertension is 0.75. Your task is to test if the claim is correct. State the null
and alternative hypotheses. correct answer Ho: p = 0.75
Ha: p ≠ 0.75
A gardener would like to know if the weight of her parsley plants is influenced by
using fertilizer. She selects 90 plants and randomly divides them into three groups
of 30 plants each. She then applies an organic biological fertilizer to the first
group, a chemical fertilizer to the second group, and no fertilizer at all to the third
group. The results are displayed in the three histograms below:
a) What type of distribution to the three histograms display?
b) Based on this information, which statistical test should the gardener use to get
the most accurate results and why? Be specific. correct answer a. normal
distribution
, b. Because the distributions are normal, the gardner should use a one-way
ANOVA with the F-ratio to compare means of the plants fed with the three
different types of fertilizer
A hospital is trying to cut down on emergency room wait times. It is interested in
the amount of time patients must wait before being called back to be examined.
An investigation committee randomly surveyed 70 patients. The sample mean
was 1.5 hours with a sample standard deviation of 0.5 hours. Identify the
following:
a. = ____ [a]
b. sx = ____ [b]
c. n = ____ [c]
d. n - 1 = ____ [d]
A 95% confidence interval (CI) was constructed with the following results:
CI: (1.3808, 1.6192)
Explain what the confidence interval means in this problem by filling in the
missing information:
We are 95% confident that the ________ [e] waiting time is between ________ [f]
and ________ [g] for patients in the emergency room before being called back to
be examined. correct answer a. sample mean = 1.5
b. sample standard deviation = 0.5
c. sample size = 70
d. degrees of freedom = n-1 = 70-1 =69
e. population mean
f. 1.38 hours
g. 1.62 hours
Questions with Accurate Answers
A 95 percent confidence interval is that range of values around a sample mean
that has a 0.95 probability of containing the true population mean. correct
answer True
A biologist has taken a random sample of a specific type of fish from a large lake
to check for levels of mercury. A 95 percent confidence interval was calculated to
be 6.8 ± 1.2 pounds. Re-read the definition of a confidence interval then choose
which of the following is true. correct answer In repeated sampling, 95 percent of
the time the true population mean of the weight of the fish will be included in this
confidence interval
A cardiologist claims the probability that a cardiac unit patient, picked at random,
has hypertension is 0.75. Your task is to test if the claim is correct. State the null
and alternative hypotheses. correct answer Ho: p = 0.75
Ha: p ≠ 0.75
A gardener would like to know if the weight of her parsley plants is influenced by
using fertilizer. She selects 90 plants and randomly divides them into three groups
of 30 plants each. She then applies an organic biological fertilizer to the first
group, a chemical fertilizer to the second group, and no fertilizer at all to the third
group. The results are displayed in the three histograms below:
a) What type of distribution to the three histograms display?
b) Based on this information, which statistical test should the gardener use to get
the most accurate results and why? Be specific. correct answer a. normal
distribution
, b. Because the distributions are normal, the gardner should use a one-way
ANOVA with the F-ratio to compare means of the plants fed with the three
different types of fertilizer
A hospital is trying to cut down on emergency room wait times. It is interested in
the amount of time patients must wait before being called back to be examined.
An investigation committee randomly surveyed 70 patients. The sample mean
was 1.5 hours with a sample standard deviation of 0.5 hours. Identify the
following:
a. = ____ [a]
b. sx = ____ [b]
c. n = ____ [c]
d. n - 1 = ____ [d]
A 95% confidence interval (CI) was constructed with the following results:
CI: (1.3808, 1.6192)
Explain what the confidence interval means in this problem by filling in the
missing information:
We are 95% confident that the ________ [e] waiting time is between ________ [f]
and ________ [g] for patients in the emergency room before being called back to
be examined. correct answer a. sample mean = 1.5
b. sample standard deviation = 0.5
c. sample size = 70
d. degrees of freedom = n-1 = 70-1 =69
e. population mean
f. 1.38 hours
g. 1.62 hours
