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[08] Module 8 Exam i rlsereen
Ashworth College | MA260 Statistical Analysis I module 8 Exam
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Written Dec 9, 2025 3:06 PM - Dec 9, 2025 4:17 PM o Attempt 1 of 2
Your quiz has been submitted successfully.
Attempt Score 95/100-95%
Overall Grade (Highest Attempt) 95/100-95%
Question 1 5/ 5 points
A market research firm reported that the mean annual earnings of all family practitioners in the United
States was $179,574. A random sample of 38 family practitioners in New York that month had mean
earnings of ¥ = $198,513 with a standard deviation of $35,113. You wish to test whether family
practitioners in New York make more than the national average.
State a conclusion regarding HOA Use the a=0.1 level of significance.
® Reject HO: the mean annual earnings appear to be greater than the national average.
Do not reject Ho: there is insufficient evidence to conclude that the mean annual earnings are greater
o than the national average.
(O There is not enough information to draw a conclusion.
Question 2 5/ 5 points
Following are outstanding credit card balances for a sample of 16 college seniors at a large university.
399 161 601 392 1,020 645 636 534
2,636455 505 615 1,213662 506 701
The dotplot of this data is below. Is it reasonable to assume that the conditions for performing a hypothesis
test are satisfied?
, 3 Exit Fullscreen
Question 3 5/ 5 points
Find the critical value for the following values of the significance level o, sample size, and alternate
hypothesis H1A
=005, n=7, Hy: p<uq
O -1.895
O -2447
® -1.943
O -1.645
Question 4 5/ 5 points
The Golden Comet is a hybrid chicken that is prized for its high egg production rate and gentle disposition.
According to recent studies, the mean rate of egg production for 1-year-old Golden Comets is 5.6
eggs/week.
Sarah has 41 1-year-old hens that are fed exclusively on natural scratch feed: insects, seeds, and plants that
the hens obtain as they range freely around the farm. Her hens exhibit a mean egg-laying rate of
5.9 eggs/day.
Sarah wants to determine whether the mean laying rate u for her hens is higher than the mean rate for all
Golden Comets. Assume the population standard deviation to be =17 eggs/day. Compute the value of the
test statistic.
O 018
O 087
® 113
O 147
Question 5 5/ 5 points
Mercury is a heavy metal that can cause severe health problems in even small concentrations. Fish and
shellfish efficiently concentrate mercury into their flesh, so it is important to monitor seafood for its
mercury content.
An extensive study conducted in 1980 concluded that the mean mercury level in oysters from the White
Bear estuary was 0.021 parts per million (ppm) with a standard deviation ¢=0032 ppm. In 2012, a sample of
47 oysters from the same estuary exhibited a mean mercury concentration of 0.017 ppm.
Can you conclude that the 2012 mercury concentration is lower than in 1980? Use the a=0.05 level of
significance.
No. There is insufficient evidence to conclude that the mercury concentration has decreased from
1980 to 2012.
(O Yes. The mercury concentration appears to be lower in 2012.
(O There is not enough information to reach a conclusion.
[08] Module 8 Exam i rlsereen
Ashworth College | MA260 Statistical Analysis I module 8 Exam
Your work has been saved and submitted
Written Dec 9, 2025 3:06 PM - Dec 9, 2025 4:17 PM o Attempt 1 of 2
Your quiz has been submitted successfully.
Attempt Score 95/100-95%
Overall Grade (Highest Attempt) 95/100-95%
Question 1 5/ 5 points
A market research firm reported that the mean annual earnings of all family practitioners in the United
States was $179,574. A random sample of 38 family practitioners in New York that month had mean
earnings of ¥ = $198,513 with a standard deviation of $35,113. You wish to test whether family
practitioners in New York make more than the national average.
State a conclusion regarding HOA Use the a=0.1 level of significance.
® Reject HO: the mean annual earnings appear to be greater than the national average.
Do not reject Ho: there is insufficient evidence to conclude that the mean annual earnings are greater
o than the national average.
(O There is not enough information to draw a conclusion.
Question 2 5/ 5 points
Following are outstanding credit card balances for a sample of 16 college seniors at a large university.
399 161 601 392 1,020 645 636 534
2,636455 505 615 1,213662 506 701
The dotplot of this data is below. Is it reasonable to assume that the conditions for performing a hypothesis
test are satisfied?
, 3 Exit Fullscreen
Question 3 5/ 5 points
Find the critical value for the following values of the significance level o, sample size, and alternate
hypothesis H1A
=005, n=7, Hy: p<uq
O -1.895
O -2447
® -1.943
O -1.645
Question 4 5/ 5 points
The Golden Comet is a hybrid chicken that is prized for its high egg production rate and gentle disposition.
According to recent studies, the mean rate of egg production for 1-year-old Golden Comets is 5.6
eggs/week.
Sarah has 41 1-year-old hens that are fed exclusively on natural scratch feed: insects, seeds, and plants that
the hens obtain as they range freely around the farm. Her hens exhibit a mean egg-laying rate of
5.9 eggs/day.
Sarah wants to determine whether the mean laying rate u for her hens is higher than the mean rate for all
Golden Comets. Assume the population standard deviation to be =17 eggs/day. Compute the value of the
test statistic.
O 018
O 087
® 113
O 147
Question 5 5/ 5 points
Mercury is a heavy metal that can cause severe health problems in even small concentrations. Fish and
shellfish efficiently concentrate mercury into their flesh, so it is important to monitor seafood for its
mercury content.
An extensive study conducted in 1980 concluded that the mean mercury level in oysters from the White
Bear estuary was 0.021 parts per million (ppm) with a standard deviation ¢=0032 ppm. In 2012, a sample of
47 oysters from the same estuary exhibited a mean mercury concentration of 0.017 ppm.
Can you conclude that the 2012 mercury concentration is lower than in 1980? Use the a=0.05 level of
significance.
No. There is insufficient evidence to conclude that the mercury concentration has decreased from
1980 to 2012.
(O Yes. The mercury concentration appears to be lower in 2012.
(O There is not enough information to reach a conclusion.
