Statistics Quiz

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Part 1 of 16 -
 
Question 1 of 23
1.0 Points
The data presented in the table below resulted from an experiment in which seeds of 5 different types were planted and the number of seeds that germinated within 5 weeks after planting was recorded for each seed type. At the .01 level of significance, is the proportion of seeds that germinate dependent on the seed type?
 
 
 
 
 
Seed Type
 
Observed Frequencies
 
Germinated
Failed to Germinate
1
31
7
2
57
33
3
87
60
4
52
44
5
10
19
 
 
 
 
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Question 2 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
 
 
 
 
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Part 2 of 16 -
 
Question 3 of 23
1.0 Points
In choosing the “best-fitting” line through a set of points in linear regression, we choose the one with the:
 
 
 
 
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Question 4 of 23
1.0 Points
A single variable X can explain a large percentage of the variation in some other variable Y when the two variables are:
 
 
 
 
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Question 5 of 23
1.0 Points
A correlation value of zero indicates.
 
 
 
 
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Part 3 of 16 -
 
Question 6 of 23
1.0 Points
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 = .725, n2 = 21, s2 = .529. 

If you compute the test value by placing the larger variance in the numerator, at the .05 level of significance, would you conclude that the risks associated with these two stocks are different? 
 
 
 
 
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Question 7 of 23
1.0 Points
Two independent samples of sizes n1 = 50 and n2 = 50 are randomly selected from two populations to test the difference between the population means, f$mu_{1}-mu _{2}f$ . The sampling distribution of the sample mean difference, f$ ar{X_{1}}- ar{X_{2}}f$ is:
 
 
 
 
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Part 4 of 16 -
 
Question 8 of 23
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?
 
 
 
 
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Question 9 of 23
1.0 Points
A two-tailed test is one where:
 
 
 
 
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Question 10 of 23
1.0 Points
Which of the following values is not typically used for f$alpha f$?
 
 
 
 
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Part 5 of 16 -
 
Question 11 of 23
1.0 Points
From a sample of 500 items, 30 were found to be defective. The point estimate of the population proportion defective will be:
 
 
 
 
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Question 12 of 23
1.0 Points
If you are constructing a confidence interval for a single mean, the confidence interval will___________ with an increase in the sample size.
 
 
 
 
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Part 6 of 16 -
 
Question 13 of 23
1.0 Points
The average height of flowering cherry trees in a nursery is 11 feet. If the heights are normally distributed with a standard deviation of 1.6, find the probability that a randomly selected cherry tree in this nursery is less than 13 feet tall.
 
 
 
 
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Part 7 of 16 -
 
Question 14 of 23
1.0 Points
A researcher surveyed college students to study their opinion about the proposed change in smoking rules. The researcher asked a group of 30 students: 12 of them supported the change, 13 of them did not, and 5 had no opinion. This is not a binomial model because...
 
 
 
 
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Part 8 of 16 -
 
Question 15 of 23
1.0 Points
If A and B are any two events with P(A) = .8 and P(B|A) = .4, then the joint probability of A and B is
 
 
 
 
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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
 BasketballFootballSoccer 
Men20253075
Women18121545
 383745120


What is the test value for this hypothesis test?

Answer:   [removed]  Round your answer to two decimal places.

What is the critical value for this hypothesis test?  

Answer:  [removed]   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:  [removed]   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. 

Data for a sample of 25 apartments in a particular neighborhood are provided in the worksheet Apartments in the Excel workbook Apartments.xlsx. Using the estimated regression equation found by using size as the predictor variable, find a point estimate for the average monthly rent for apartments having 1,000 square feet of space. Place your answer, rounded to the nearest whole dollar, in the blank. [removed]  When entering your answer do not use any labels or symbols. Simply provide the numerical value. For example, 123 would be a legitimate entry.

Apartments.xlsx


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. 

Q-Mart is interested in comparing its male and female customers. Q-Mart would like to know if the amount of money spent by its female charge customers differs, on average, from the amount spent by its male charge customers. 

To answer this question, an analyst collected random samples of 25 female customers and 22 male customers. Based on these samples, on average, the 25 women charge customers spent $102.23 and the 22 men charge customers spent $86.46. Moreover, the sample standard deviation of the amount charged by the 25 women was $93.393, and the sample standard deviation of the amount charged by the 22 men was $59.695. 

Suppose, using a 10% level of significance, you wish to know if there is sufficient evidence for Q-Mart to conclude that, on average, the amount spent by women charge customers differs from the amount spent by men charge customers. That is suppose you wish to test 

H0: f$mu _{W} = mu _{M}f$ versus H1: f$mu _{W}   eq mu _{M}f$

Assuming that the amounts spent by female and male charge customers at Q-Mart are normally distributed, based on the procedure advocated by Bluman, what is/are the critical values that you would use to conduct this test of hypothesis? Place your answer, rounded to 3 decimal places, in the blank. If there are two critical values, place only the positive value in the blank. For example, 2.035 would be a legitimate entry.   [removed] 

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.  [removed]   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 marketing research consultant hired by Coca-Cola is interested in determining the proportion of customers who favor Coke over other soft drinks. A random sample of 400 consumers was selected from the market under investigation and showed that 53% favored Coca-Cola over other brands. 

Compute a 95% confidence interval for the true proportion of people who favor Coke. Place your LOWER limit, rounded to 3 decimal places, in the first blank [removed] . For example, .345 would be a legitimate entry. Place your UPPER limit in the second blank [removed] . For example, .456 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. 

If a gambler rolls two dice and gets a sum of four, he wins $10; and if he gets a sum of three, he wins $25. The cost to play the game is $5. What is the expectation of this game?
 
Place your answer, rounded to two decimal places, in the blank.  [removed]   When entering your answer do not use a dollar sign. However, if the expected payoff is negative be sure to use a minus sign. For example, -1.23 would be a legitimate entry. 

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. 

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 H0f$mu leq f$ 1500 versus H1f$mu  f$> 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. [removed] 

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. 

An ice cream vendor sells three flavors: chocolate, strawberry, and vanilla. Forty five percent of the sales are chocolate, while 30% are strawberry, with the rest vanilla flavored. Sales are by the cone or the cup. The percentages of cones sales for chocolate, strawberry, and vanilla, are 75%, 60%, and 40%, respectively. For a randomly selected sale, define the following events:

f$A_{1}f$ = chocolate chosen
f$A_{2}f$ = strawberry chosen
f$A_{3}f$ = vanilla chosen
f$Bf$ = ice cream on a cone
f$ ar{B}=f$ice cream in a cup

Find the probability that the ice cream was vanilla flavor, given that it was sold in a cup.  Place your answer, rounded to 4 decimal places, in the blank. For exampe, 0.3456 would be a legitimate entry. [removed]
    • Posted: 5 years ago
    • Due: 
    • Budget: $40
    Answers 1

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