Question 1 of 23
1.0 Points
A company operates four machines during three shifts each day. From production records, the data in the table below were collected. At the .05 level of significance test to determine if the number of breakdowns is independent of the shift.
Machine
Shift
A
B
C
D
1
41
20
12
16
2
31
11
9
14
3
15
17
16
10
A.The number of breakdowns is dependent on the shift, because the test value 11.649 is less than the critical value of 12.592.
B.The claim that the number of breakdowns is independent of the shift cannot be rejected, because the test value 11.649 is less than the critical value of 12.592.
C.The number of breakdowns is dependent on the shift, because the p-value is .07.
D.The number of breakdowns is independent of the shift, because the test value 12.592 is greater than the critical value of 11.649.
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Question 2 of 23
1.0 Points
The chi-square goodness-of-fit test can be used to test for:
A.significance of sample statistics
B.difference between population variances
C.normality
D.difference between population means
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Part 2 of 16 -
Question 3 of 23
1.0 Points
The regression line y' = -3 + 2.5 X has been fitted to the data points (28, 60), (20, 50), (10, 18), and (25, 55). The sum of the squared residuals will be:
A.20.25
B.49.00
C.16.00
D.94.25
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Question 4 of 23
1.0 Points
Data for a sample of 25 apartments in a particular neighborhood are provided in the worksheet Apartments in the Excel workbook Apartments.xlsx. Using that data, find the estimated regression equation which can be used to estimate the monthly rent for apartments in this neighborhood using size as the predictor variable.
Apartments.xlsx
A.\f$\hat{y}= \f$ 177.12 + 0.8500(size)
B.\f$\hat{y}= \f$ 197.12 + 2.065(size)
C.\f$\hat{y}= \f$ 1.065 + 177.12(size)
D. \f$\hat{y}= \f$ 177.12 + 1.065(size)
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Question 5 of 23
1.0 Points
____________ is/are especially helpful in identifying outliers.
A.Scatterplots
B.Normal curves
C.Linear regression
D.Regression analysis
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Part 3 of 16 -
Question 6 of 23
1.0 Points
A pharmaceutical company is testing the effectiveness of a new drug for lowering cholesterol. As part of this trial, they wish to determine whether there is a difference between the effectiveness for women and for men. Assume α = 0.05. What is the test value?
Women
Men
Sample size
50
80
Mean effect
7
6.95
Sample variance
3
4
A.t = 3.252
B.t = 0.151
C.z = 0.455
D.z = 0.081
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Question 7 of 23
1.0 Points
Multiple myeloma or blood plasma cancer is characterized by increased blood vessel formulation in the bone marrow that is a prognostic factor in survival. One treatment approach used for multiple myeloma is stem cell transplantation with the patient’s own stem cells. The following data represent the bone marrow microvessel density for a sample of 7 patients who had a complete response to a stem cell transplant as measured by blood and urine tests. Two measurements were taken: the first immediately prior to the stem cell transplant, and the second at the time of the complete response.
Patient
1
2
3
4
5
6
7
Before
158
189
202
353
416
426
441
After
284
214
101
227
290
176
290
At the .01 level of significance, is there sufficient evidence to conclude that the mean bone marrow microvessel density is higher before the stem cell transplant than after the stem cell transplant?
A.No
B.Yes
C.Cannot Determine
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Part 4 of 16 -
Question 8 of 23
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.0.7563
B.0.4874
C.0.6874
D.0.2437
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Question 9 of 23
1.0 Points
A type I error occurs when the:
A.null hypothesis is incorrectly rejected when it is true
B.null hypothesis is incorrectly accepted when it is false
C.sample mean differs from the population mean
D.test is biased
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Question 10 of 23
1.0 Points
The hypothesis that an analyst is trying to prove is called the:
A.level of significance
B.alternative hypothesis
C.elective hypothesis
D.quality of the researcher
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Part 5 of 16 -
Question 11 of 23
1.0 Points
A previous study of nickels showed that the standard deviation of the weight of nickels is 150 milligrams. How many nickels does a coin counter manufacturer need to weigh so that she can be 98% confident that her sample mean is within 25 milligrams of the true average weight of a nickel?
A.36
B.196
C.239
D.139
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Question 12 of 23
1.0 Points
A food snack manufacturer samples 15 bags of pretzels off the assembly line and weighed their contents. If the sample mean is 10.0 and the sample standard deviation is 0.15, find the 95% confidence interval estimate for the true mean.
A.(9.96, 10.04)
B.(9.68, 10.32)
C.(9.97, 10.80)
D.(9.92, 10.08)
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Part 6 of 16 -
Question 13 of 23
1.0 Points
The normal distribution is:
A.a density function of a discrete random variable
B.a binomial distribution with only one parameter
C.the single most important distribution in statistics
D.a discrete distribution
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Part 7 of 16 -
Question 14 of 23
1.0 Points
Suppose that 50 identical batteries are being tested. After 8 hours of continuous use, assume that a given battery is still operating with a probability of 0.70 and has failed with a probability of 0.30.
What is the probability that greater than 30 batteries will last at least 8 hours?
A.0.8594
B.0.9152
C.0.0848
D.0.9522
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Part 8 of 16 -
Question 15 of 23
1.0 Points
If one tosses a coin enough times, the proportion of "heads" will approach 0.5. This is an example of:
A.the Empirical Rule
B.the Central Limit Theorem
C.subjective probabilities
D.the Law of Large Numbers
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Part 9 of 16 -
Question 16 of 23
3.0 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 sport preference poll yielded the following data for men and women. Use a 5% significance level and test to determine if sport preference and gender are independent.
Sport Preferences of Men and Women Basketball Football Soccer
Men 20 25 30 75
Women 18 12 15 45
38 37 45 120
What is the test value for this hypothesis test?
Answer: Round your answer to two decimal places.
What is the critical value for this hypothesis test?
Answer: Round your answer to two decimal places.
What is the conclusion for this hypothesis test? Choose one.
1. There is sufficient evidence to support the claim that one's sport preference is dependent on one's gender.
2. There is not sufficient evidence to support the claim that one's sport preference is dependent on one's gender.
Answer: Enter only a 1 or 2 for your answer.
Part 10 of 16 -
Question 17 of 23
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 company has observed that there is a linear relationship between indirect labor expense (ILE) , in dollars, and direct labor hours (DLH). Data for direct labor hours and indirect labor expense for 18 months are given in the file ILE_and_DLH.xlsx
Treating ILE as the response variable, use regression to fit a straight line to all 18 data points. What values for the intercept (a) and slope (b) do you obtain?
Place your answers, rounded to 3 decimal places, in the blanks provided. Do not use any stray punctuation marks. For example, 34.567 would be a legitimate entry.
intercept (a) =
slope(b) =
Part 11 of 16 -
Question 18 of 23
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.
An investor wants to compare the risks associated with two different stocks. One way to measure the risk of a given stock is to measure the variation in the stock’s daily price changes.
In an effort to test the claim that the variance in the daily stock price changes for stock 1 is different from the variance in the daily stock price changes for stock 2, the investor obtains a random sample of 21 daily price changes for stock 1 and 21 daily price changes for stock 2.
The summary statistics associated with these samples are: n1 = 21, s1 = .849, n2 = 21, s2 = .529.
If you follow Bluman's advice and place the larger variance in the numerator, what is the test value associated with this test of hypothesis? Place your answer, rounded to 3 decimal places, in the blank. For example, 3.456 would be a legitimate entry.
Part 12 of 16 -
Question 19 of 23
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.
In a particular region of Cape Cod, it is known that lobstermen trap on average of 32 pounds of lobster per day with a standard deviation of four pounds. If a random sample of 30 lobster fishermen is selected, what is the probability that their average catch is less than 31.5 pounds?
Place your answer, rounded to four decimal places, in the blank. When entering your answer do not use any labels or symbols other than a decimal point. Simply provide the numerical value. For example, 0.1234 would be a legitimate entry.
Part 13 of 16 -
Question 20 of 23
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 sample of 40 country CD recordings of Willie Nelson has been examined. The average playing time of these recordings is 51.3 minutes, and the standard deviation is s = 5.8 minutes.
Using an appropriate t-multiplier, construct a 95% confidence interval for the mean playing time of all Willie Nelson recordings.
Place your LOWER limit, in minutes, rounded to 2 decimal places, in the first blank. For example, 56.78 would be a legitimate entry. .
Place your UPPER limit, in minutes, rounded to 2 decimal places, in the second blank. For example, 67.89 would be a legitimate entry.
Part 14 of 16 -
Question 21 of 23
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.
It has been reported that 3% of all cars on the highway are traveling at speeds in excess of 70 mph. If the speeds of four random automobiles are measured via radar, what is the probability that at least one car is going over 70 mph? Place your answer, rounded to four decimal places, in the space.
Part 15 of 16 -
Question 22 of 23
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: Round your answer to four decimal places as necessary.
Part 16 of 16 -
Question 23 of 23
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 reading list for a course contains 20 articles. How many ways are there to choose three articles from this list? Place your answer in the blank. Do not use any decimal places or commas. For example, 45 would be a legitimate entry.
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