Question 1 of 20
0.0/ 1.0 Points
Suppose that the mean time for a certain car to go from 0 to 60 miles per hour was 7.7 seconds. Suppose that you want to test the claim that the average time to accelerate from 0 to 60 miles per hour is longer than 7.7 seconds. What would you use for the alternative hypothesis?
A.H1: \f$\mu \f$ = 7.7 seconds
B.H1: \f$\mu \f$ > 7.7 seconds
C.H1: \f$\mu \geq \f$ 7.7 seconds
Incorrect D.H1: \f$\mu \f$ < 7.7 seconds
Answer Key: B
Question 2 of 20
1.0/ 1.0 Points
In an article appearing in Today’s Health a writer states that the average number of calories in a serving of popcorn is 75. To determine if the average number of calories in a serving of popcorn is different from 75, a nutritionist selected a random sample of 20 servings of popcorn and computed the sample mean number of calories per serving to be 78 with a sample standard deviation of 7.
State the null and alternative hypotheses.
A.H0: \f$\mu \f$ \f$\leq \f$ 75, H1: \f$\mu \f$ > 75
Correct B.H0: \f$\mu \f$ = 75, H1: \f$\mu \f$ ≠ 75
C.H0: \f$\mu \f$ \f$\geq \f$ 75, H1: \f$\mu \f$ < 75
D.H0: \f$\mu \f$ = 75, H1: \f$\mu \f$ > 75
Answer Key: B
Question 3 of 20
0.0/ 1.0 Points
A lab technician is tested for her consistency by taking multiple measurements of cholesterol levels from the same blood sample. The target accuracy is a variance in measurements of 1.2 or less. If the lab technician takes 16 measurements and the variance of the measurements in the sample is 2.2, does this provide enough evidence to reject the claim that the lab technician’s accuracy is within the target accuracy?
State the null and alternative hypotheses.
Incorrect A.H0: s2 ≥ 1.2, H1: s2 ≠ 1.2
B.H0: s2 ≠ 1.2, H1: s2 = 1.2
C.H0: s2 < 1.2, H1: s2 ≠ 1.2
D.H0: s2 ≤ 1.2, H1: s2 > 1.2
Answer Key: D
Question 4 of 20
0.0/ 1.0 Points
The “Pizza Hot” manager commits a Type I error if he/she is
A.switching to new style when it is no better than old style
B.staying with old style when new style is no better than old style
C.switching to new style when it is better than old style
Incorrect D.staying with old style when new style is better
Answer Key: A
Question 5 of 20
1.0/ 1.0 Points
In an article appearing in Today’s Health a writer states that the average number of calories in a serving of popcorn is 75. To determine if the average number of calories in a serving of popcorn is different from 75, a nutritionist selected a random sample of 20 servings of popcorn and computed the sample mean number of calories per serving to be 78 with a sample standard deviation of 7.
At the a = .05 level of significance, does the nutritionist have enough evidence to reject the writer’s claim?
Correct A.No
B.Yes
C.Cannot Determine
Answer Key: A
Question 6 of 20
1.0/ 1.0 Points
Results from previous studies showed 79% of all high school seniors from a certain city plan to attend college after graduation. A random sample of 200 high school seniors from this city reveals that 162 plan to attend college. Does this indicate that the percentage has increased from that of previous studies? Test at the 5% level of significance.
What is the p-value associated with your test of hypothesis?
A.0.6874
Correct B.0.2437
C.0.7563
D.0.4874
Answer Key: B
Question 7 of 20
1.0/ 1.0 Points
A two-tailed test is one where:
A.results in only one direction can lead to rejection of the null hypothesis
B.negative sample means lead to rejection of the null hypothesis
C.no results lead to the rejection of the null hypothesis
Correct D.results in either of two directions can lead to rejection of the null hypothesis
Answer Key: D
Question 8 of 20
1.0/ 1.0 Points
Smaller p-values indicate more evidence in support of the:
A.quality of the researcher
B.null hypothesis
C.the reduction of variance
Correct D.alternative hypothesis
Answer Key: D
Question 9 of 20
1.0/ 1.0 Points
Which of the following statements are true of the null and alternative hypotheses?
A.It is possible for both hypotheses to be true
B.Both hypotheses must be true
Correct C.Exactly one hypothesis must be true
D.It is possible for neither hypothesis to be true
Answer Key: C
Question 10 of 20
1.0/ 1.0 Points
A type II error occurs when:
A.the sample mean differs from the population mean
B.the null hypothesis is incorrectly rejected when it is true
C.the test is biased
Correct D.the null hypothesis is incorrectly accepted when it is false
Answer Key: D
Question 11 of 20
1.0/ 1.0 Points
If a teacher is trying to prove that a new method of teaching economics is more effective than a traditional one, he/she will conduct a:
A.confidence interval
B.two-tailed test
Correct C.one-tailed test
D.point estimate of the population parameter
Answer Key: C
Part 2 of 3 - 3.0/ 6.0 Points
Question 12 of 20
1.0/ 1.0 Points
Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000), "E" or "e" (used in scientific notation). NOTE: For scientific notation, a period MUST be used as the decimal point marker.
Complex numbers should be in the form (a + bi) where "a" and "b" need to have explicitly stated values.
For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not.
At a university, the average cost of books per student has been $400 per student per semester. The Dean of Students believes that the costs are increasing and that the average is now greater than $400. He surveys a sample of 40 students and finds that for the most recent semester their average cost was $430 with a standard deviation of $80. What is the test value for this hypothesis test?
Test value: Correct2.37 Round your answer to two decimal places as necessary.
Answer Key: 2.36|2.37
Question 13 of 20
0.0/ 1.0 Points
Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000), "E" or "e" (used in scientific notation). NOTE: For scientific notation, a period MUST be used as the decimal point marker.
Complex numbers should be in the form (a + bi) where "a" and "b" need to have explicitly stated values.
For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not.
A survey determines that mint chocolate chip is the favorite ice cream flavor of 6% of consumers. An ice cream shop determines that of 260 customers, 20 customers stated their preference for mint chocolate chip.
Find the P-value that would be used to determine if the percentage of customers who prefer mint chocolate chip ice has increased at a 5% level of significance.
P-value: Correct.4681 Round your answer to four decimal places as necessary.
Answer Key: 0.1251|0.1253
Feedback: This is a right-tail hypothesis test with a test statistic of z = 1.149017.
Question 14 of 20
1.0/ 1.0 Points
Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000), "E" or "e" (used in scientific notation). NOTE: For scientific notation, a period MUST be used as the decimal point marker.
Complex numbers should be in the form (a + bi) where "a" and "b" need to have explicitly stated values.
For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not.
The ABC battery company claims that their batteries last at least 100 hours, on average. Your experience with their batteries has been somewhat different, so you decide to conduct a test to see if the company's claim is true. You believe that the mean life is actually less than the 100 hours the company claims. You decide to collect data on the average battery life (in hours) of a random sample of n = 20 batteries. Some of the information related to the hypothesis test is presented below.
Test of H0: f$mu geq f$ 100 versus H1: f$mu < f$ 100
Sample mean 98.5
Std error of mean 0.777
Assuming the life length of batteries is normally distributed, what is the value of the test statistic used to conduct your test of hypothesis? Place your answer, rounded to 3 decimal places in the blank. For example, -2.345 would be a legitimate entry. Correct-1.931
Answer Key: -1.932|-1.930
Question 15 of 20
1.0/ 1.0 Points
Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000), "E" or "e" (used in scientific notation). NOTE: For scientific notation, a period MUST be used as the decimal point marker.
Complex numbers should be in the form (a + bi) where "a" and "b" need to have explicitly stated values.
For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not.
The CEO of a software company is committed to expanding the proportion of highly qualified women in the organization’s staff of salespersons. He believes that the proportion of women in similar sales positions across the country is less than 45%. Hoping to find support for his belief, he directs you to test
H0: p f$geq f$ .45 vs H1: p < .45.
In doing so, you collect a random sample of 50 salespersons employed by his company, which is thought to be representative of sales staffs of competing organizations in the industry. The collected random sample of size 50 showed that only 18 were women.
What is the smallest level of significance at which you could reject the null in favor of the alternative hypothesis? Place your answer, rounded to 4 decimal places, in the blank. For example, 0.1234 would be a legitimate entry. Correct0.1005
Answer Key: .1003|.1020
Question 16 of 20
0.0/ 1.0 Points
Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000), "E" or "e" (used in scientific notation). NOTE: For scientific notation, a period MUST be used as the decimal point marker.
Complex numbers should be in the form (a + bi) where "a" and "b" need to have explicitly stated values.
For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not.
A statistician wishes to test the claim that the standard deviation of the weights of firemen is less than 25 pounds. To do so, she selected a random sample of 20 firemen and found s = 23.2 pounds.
Assuming that the weights of firemen are normally distributed, if the statistician wanted to test her research hypothesis at the .05 level of significance, what is the critical value?
Place your answer, rounded to 3 decimal places, in the blank. For example, 12.345 would be a legitimate entry. Correct2.064
Answer Key: 10.117
Question 17 of 20
0.0/ 1.0 Points
Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000), "E" or "e" (used in scientific notation). NOTE: For scientific notation, a period MUST be used as the decimal point marker.
Complex numbers should be in the form (a + bi) where "a" and "b" need to have explicitly stated values.
For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not.
Suppose a firm that produces light bulbs wants to know whether it can say that its light bulbs typically last more than 1500 hours. Hoping to find support for their claim, the firm collects a random sample of n = 25 light bulbs and records the lifetime (in hours) of each bulb. The information related to the hypothesis test is presented below.
Test of H0: f$mu leq f$ 1500 versus H1: f$mu f$ > 1500
Sample mean 1509.5
Std error of mean 4.854
Assuming the life length of this type of lightbulb is normally distributed, if you wish to conduct this test using a .05 level of significance, what is the critical value that you should use? Place your answer, rounded to 3 decimal places in the blank. For example, 1.234 would be a legitimate entry. Correct1.7109
Answer Key: 1.711
Part 3 of 3 - 3.0/ 3.0 Points
Question 18 of 20
1.0/ 1.0 Points
An alternative or research hypothesis is usually the hypothesis a researcher wants to prove.
Correct
True
False
Answer Key: True
Question 19 of 20
1.0/ 1.0 Points
The probability of making a Type I error and the level of significance are the same.
Correct
True
False
Answer Key: True
Question 20 of 20
1.0/ 1.0 Points
Using the confidence interval when conducting a two-tailed test for the population proportion p, we reject the null hypothesis if the hypothesized value for p falls inside the confidence interval.
Correct
True
False
Answer Key: False
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