# Ashworth STAT260 exam 6

December 14, 2016

Question
Part 1 of 2 –

32.5/ 50.0 Points

Question 1 of 40

0.0/ 2.5 Points

A bag contains four chips of which one is red, one is blue, one is green, and one is yellow. A chip is selected at random from the bag and then replaced in the bag. A second chip is then selected at random. Make a list of the possible outcomes (for example, RB represents the outcome red chip followed by blue chip) and use your list to determine the probability that the two chips selected are the same color. (Hint: There are 16 possible outcomes.)

A. 1/4

B. 3/4

C. 2/16

D. 3/16

Question 2 of 40

2.5/ 2.5 Points

If you flip a coin three times, the possible outcomes are HHH, HHT, HTH,
HTT, THH, THT, TTH, TTT. What is the probability of getting at least one head?

A. 4/9

B. 5/6

C. 7/8

D. 5/8

Question 3 of 40

2.5/ 2.5 Points

Sammy and Sally each carry a bag containing a banana, a chocolate bar, and a licorice stick. Simultaneously, they take out a single food item and consume it. The possible pairs of food items that Sally and Sammy consumed are as follows.

chocolate bar – chocolate bar

licorice stick – chocolate bar

banana – banana

chocolate bar – licorice stick

licorice stick – licorice stick

chocolate bar – banana

banana – licorice stick

licorice stick – banana

banana – chocolate bar

Find the probability that no chocolate bar was eaten.

A. 4/9

B. 5/9

C. 7/9

D. 5/8

Question 4 of 40

0.0/ 2.5 Points

If a person is randomly selected, find the probability that his or her birthday is not in May. Ignore leap years. There are 365 days in a year. Express your answer as a fraction.

A. 335/365

B. 334/365

C. 336/365

D. 30/365

Question 5 of 40

2.5/ 2.5 Points

On a multiple choice test, each question has 6 possible answers. If you make a random guess on the first question, what is the probability that you are correct?

A. 1/5

B. 1/6

C. 1/4

D. 2/5

Question 6 of 40

2.5/ 2.5 Points

A study of students taking Statistics 101 was done. Four hundred students who studied for more than 10 hours averaged a B. Two hundred students who studied for less than 10 hours averaged a C. This difference was significant at the 0.01 level. What does this mean?

A. The probability that the difference was due to chance alone is greater than 0.01.

B. There is less than a 0.01 chance that the first group’s grades were better by chance alone.

C. The improvement was due to the fact that more people studied.

D. There is not enough information to make any conclusion.

Question 7 of 40

2.5/ 2.5 Points

The probability that Luis will pass his statistics test is 0.94. Find the probability that he will fail his statistics test.

A. 0.02

B. 0.05

C. 0.94

D. 0.06

Question 8 of 40

2.5/ 2.5 Points

If you flip a coin three times, the possible outcomes are HHH, HHT, HTH, HTT, THH, THT, TTH, TTT. What is the probability of getting at least two tails?

A. 1/2

B. 2/3

C. 3/4

D. 4/9

Question 9 of 40

0.0/ 2.5 Points

A 28-year-old man pays \$125 for a one-year life insurance policy with coverage of \$140,000. If the probability that he will live through the year is 0.9994, to the nearest dollar, what is the man’s expected value for the insurance policy?

A. \$139,916

B. ?\$41

C. \$84

D. ?\$124

Question 10 of 40

0.0/ 2.5 Points

A study of two types of weed killers was done on two identical weed plots. One weed killer killed 15% more weeds than the other. This difference was significant at the 0.05 level. What does this mean?

A. The improvement was due to the fact that there were more weeds in one study.

B. The probability that the difference was due to chance alone is greater than 0.05.

C. The probability that one weed killer performed better by chance alone is less than 0.05.

D. There is not enough information to make any conclusion.

Question 11 of 40

2.5/ 2.5 Points

Jody checked the temperature 12 times on Monday, and the last digit of the temperature was odd six times more than it was even. On Tuesday, she checked it 18 times and the last digit was odd eight times more than it was even. Determine which series is closer to the 50/50 ratio of odd/even expected of such a series of temperature checks.

A. The Monday series is closer because 1/6 is closer to 1/2 than is 1/8.

B. The Monday series is closer because 6/12 is closer to 0.5 than is 8/18.

C. The Tuesday series is closer because the 13/18 is closer to 0.5 than is 9/12.

D. The series closest to the theoretical 50/50 cannot be determined without knowing the number of odds and evens in each series.

Question 12 of 40

0.0/ 2.5 Points

The data set represents the income levels of the members of a country club. Estimate the probability that a randomly selected member earns at least \$98,000.

112,000 126,000 90,000 133,000 94,000 112,000 98,000 82,000 147,000 182,000 86,000 105,000

140,000 94,000 126,000 119,000 98,000 154,000 78,000 119,000

A. 0.4

B. 0.6

C. 0.66

D. 0.7

Question 13 of 40

2.5/ 2.5 Points

A sample space consists of 46 separate events that are equally likely. What is the probability of each?

A. 1/24

B. 1/46

C. 1/32

D. 1/18

Question 14 of 40

0.0/ 2.5 Points

In a poll, respondents were asked whether they had ever been in a car accident. 220 respondents indicated that they had been in a car accident and 370 respondents said that they had not been in a car accident. If one of these respondents is randomly selected, what is the probability of getting someone who has been in a car accident? Round to the nearest thousandth.

A. 0.384

B. 0.380

C. 0.373

D. 0.370

Question 15 of 40

2.5/ 2.5 Points

Suppose you buy 1 ticket for \$1 out of a lottery of 1000 tickets where the prize for the one winning ticket is to be \$500. What is your expected value?

A. \$0.00

B. ?\$0.40

C. ?\$1.00

D. ?\$0.50

Question 16 of 40

2.5/ 2.5 Points

A bag contains 4 red marbles, 3 blue marbles, and 7 green marbles. If a marble is randomly selected from the bag, what is the probability that it is blue?

A. 2/11

B. 3/11

C. 5/14

D. 3/14

Question 17 of 40

2.5/ 2.5 Points

In the first series of rolls of a die, the number of odd numbers exceeded the number of even numbers by 5. In the second series of rolls of the same die, the number of odd numbers exceeded the number of even numbers by 11. Determine which series is closer to the 50/50 ratio of odd/even expected of a fairly rolled die.

A. The second series is closer because the difference between odd and even numbers is greater than the difference for the first series.

B. The first series is closer because the difference between odd and even numbers is less than the difference for the second series.

C. Since 1/2 > 1/5 > 1/11, the first series is closer.

D. The series closer to the theoretical 50/50 cannot be determined unless the total number of rolls for both series is given.

Question 18 of 40

2.5/ 2.5 Points

Of 1308 people who came into a blood bank to give blood, 314 people had high blood pressure. Estimate the probability that the next person who comes in to give blood will have high blood pressure (to 3 decimal places).

A. 0.250

B. 0.490

C. 0.240

D. 0.160

Question 19 of 40

0.0/ 2.5 Points

Suppose you have an extremely unfair coin: the probability of a head is 1/5, and the probability of a tail is 4/5. If you toss the coin 40 times, how many heads do you expect to see?

A. 8

B. 6

C. 5

D. 4

Question 20 of 40

2.5/ 2.5 Points

Joe dealt 20 cards from a standard 52-card deck, and the number of red cards exceeded the number of black cards by 8. He reshuffled the cards and dealt 30 cards. This time, the number of red cards exceeded the number of black cards by 10. Determine which deal is closer to the 50/50 ratio of red/black expected of fairly dealt hands from a fair deck and why.

A. The first series is closer because 1/10 is farther from 1/2 than is 1/8.

B. The series closer to the theoretical 50/50 cannot be determined unless the number of red and black cards for each deal is given.

C. The second series is closer because 20/30 is closer to 1/2 than is 14/20.

D. The first series is closer because the difference between red and black is smaller than the difference in the second series.

Part 2 of 2 –

17.5/ 50.0 Points

Question 21 of 40

2.5/ 2.5 Points

Eleven female college students are selected at random and asked their heights. The heights (in inches) are as follows:

67, 59, 64, 69, 65, 65, 66, 64, 62, 64, 62

Estimate the mean height of all female students at this college. Round your answer to the nearest tenth of an inch if necessary.

A. It is not possible to estimate the population mean from this sample data

B. 64.3 inches

C. 64.9 inches

D. 63.7 inches

Question 22 of 40

0.0/ 2.5 Points

A researcher wishes to estimate the proportion of college students who cheat on exams. A poll of 560 college students showed that 27% of them had, or intended to, cheat on examinations. Find the 95% confidence interval.

A. 0.2323 to 0.3075

B. 0.2325 to 0.3075

C. 0.2325 to 0.3185

D. 0.2323 to 0.3185

Question 23 of 40

0.0/ 2.5 Points

Select the best fit line on the scatter diagram below.

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A. A

B. B

C. C

D. All of the lines are equally good

Question 24 of 40

0.0/ 2.5 Points

Select the best estimate of the correlation coefficient for the data depicted in the scatter diagram.

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A. -0.9

B. 0.9

C. 0.5

D. -0.5

Question 25 of 40

2.5/ 2.5 Points

Which graph has two groups of data, correlations within each group, but no correlation among all the data?

A.

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B.

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C.

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D.

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Question 26 of 40

0.0/ 2.5 Points

In a poll of 400 voters in a certain state, 61% said that they opposed a voter ID bill that might hinder some legitimate voters from voting. The margin of error in the poll was reported as 4 percentage points (with a 95% degree of confidence). Which statement is correct?

A. The reported margin of error is consistent with the sample size.

B. There is not enough information to determine whether the margin of error is consistent with the sample size.

C. The sample size is too small to achieve the stated margin of error.

D. For the given sample size, the margin of error should be smaller than stated.

Question 27 of 40

0.0/ 2.5 Points

A population proportion is to be estimated. Estimate the minimum sample size needed to achieve a margin of error E = 0.01with a 95% degree of confidence.

A. 7,000

B. 8,000

C. 9,000

D. 10,000

Question 28 of 40

2.5/ 2.5 Points

A sample of nine students is selected from among the students taking a particular exam. The nine students were asked how much time they had spent studying for the exam and the responses (in hours) were as follows:

18, 7, 10, 13, 12, 16, 5, 20, 21

Estimate the mean study time of all students taking the exam. Round your answer to the nearest tenth of an hour if necessary.

A. 13 hours

B. 12.2 hours

C. 13.6 hours

D. It is not possible to estimate the population mean from this sample data

Question 29 of 40

0.0/ 2.5 Points

Which line of the three shown in the scatter diagram below fits the data best?

.jpg” alt=”https://study.ashworthcollege.edu/access/content/group/8ef8b2f7-197d-41de-a4c4-db81a717c013/v9/Images/Lesson%206%20Exam/MA260%20Lesson%206%20exam%20question%2015.JPG”>

A. A

B. B

C. C

D. All the lines are equally good

Question 30 of 40

0.0/ 2.5 Points

Select the best estimate of the correlation coefficient for the data depicted in the scatter diagram.

.jpg” alt=”https://study.ashworthcollege.edu/access/content/group/8ef8b2f7-197d-41de-a4c4-db81a717c013/v9/Images/Lesson%206%20Exam/MA260%20Lesson%206%20exam%20question%2014.JPG”>

A. 0.60

B. -0.97

C. 0.10

D. -0.60

Question 31 of 40

0.0/ 2.5 Points

The scatter plot and best-fit line show the relation among the data for the price of a stock (y) and employment (x) in arbitrary units. The correlation coefficient is 0.8. Predict the stock price for an employment value of 6.

.jpg” alt=”https://study.ashworthcollege.edu/access/content/group/8ef8b2f7-197d-41de-a4c4-db81a717c013/v9/Images/Lesson%206%20Exam/MA260%20Lesson%206%20exam%20question%207.JPG”>

A. 8.8

B. 6.2

C. 8.2

D. None of the values are correct

Question 32 of 40

0.0/ 2.5 Points

The scatter plot and best-fit line show the relation among the number of cars waiting by a school (y) and the amount of time after the end of classes (x) in arbitrary units. The correlation coefficient is -0.55. Use the line of best fit to predict the number of cars at time 4 after the end of classes.

.jpg” alt=”https://study.ashworthcollege.edu/access/content/group/8ef8b2f7-197d-41de-a4c4-db81a717c013/v9/Images/Lesson%206%20Exam/MA260%20Lesson%206%20exam%20question%2013.JPG”>

A. 7.0

B. 6.0

C. 8.0

D. 3.5

Question 33 of 40

0.0/ 2.5 Points

The graph shows a measure of fitness (y) and miles walked weekly. Identify the probable cause of the correlation.

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A. The correlation is coincidental.

B. There is a common underlying cause of the correlation.

C. There is no correlation between the variables.

D. Walking is a direct cause of the fitness.

Question 34 of 40

2.5/ 2.5 Points

Sample size = 400, sample mean = 44, sample standard deviation = 16. What is the margin of error?

A. 1.4

B. 1.6

C. 2.2

D. 2.6

Question 35 of 40

0.0/ 2.5 Points

30% of the fifth grade students in a large school district read below grade level. The distribution of sample proportions of samples of 100 students from this population is normal with a mean of 0.30 and a standard deviation of 0.045. Suppose that you select a sample of 100 fifth grade students from this district and find that the proportion that reads below grade level in the sample is 0.36. What is the probability that a second sample would be selected with a proportion less than 0.36?

A. 0.8932

B. 0.8920

C. 0.9032

D. 0.9048

Question 36 of 40

2.5/ 2.5 Points

Select the best fit line on the scatter diagram below.

.jpg” alt=”https://study.ashworthcollege.edu/access/content/group/8ef8b2f7-197d-41de-a4c4-db81a717c013/v9/Images/Lesson%206%20Exam/MA260%20Lesson%206%20exam%20question%205.JPG”>

A. A

B. B

C. C

D. None of the lines is the line of best fit

Question 37 of 40

0.0/ 2.5 Points

A sample of 64 statistics students at a small college had a mean mathematics ACT score of 28 with a standard deviation of 4. Estimate the mean mathematics ACT score for all statistics students at this college. Give the 95% confidence interval.

A. 28.0 to 30.0

B. 25.0 to 27.0

C. 29.0 to 31.0

D. 27.0 to 29.0

Question 38 of 40

0.0/ 2.5 Points

Select the best estimate of the correlation coefficient for the data depicted in the scatter diagram.

.jpg” alt=”https://study.ashworthcollege.edu/access/content/group/8ef8b2f7-197d-41de-a4c4-db81a717c013/v9/Images/Lesson%206%20Exam/MA260%20Lesson%206%20exam%20question%208.JPG”>

A. -0.9

B. 0.1

C. 0.5

D. 0.9

Question 39 of 40

2.5/ 2.5 Points

The scatter plot and best-fit line show the relation between the price per item (y) and the availability of that item (x) in arbitrary units. The correlation coefficient is -0.95. Determine the amount of variation in pricing explained by the variation in availability.

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A. 5%

B. 10%

C. 95%

D. 90%

Question 40 of 40

2.5/ 2.5 Points

Which point below would be an outlier if it were on the following graph?

.jpg” alt=”https://study.ashworthcollege.edu/access/content/group/8ef8b2f7-197d-41de-a4c4-db81a717c013/v9/Images/Lesson%206%20Exam/MA260%20Lesson%206%20exam%20question%202.JPG”>

A. (25, 20)

B. (5, 12)

C. (7, 5)

D. (5, 3)