ashworth college MA260 online exam 6 latest 2015 december

Part 1 of 2 - 40.0/ 50.0 Points

Question 1 of 40

2.5/ 2.5 Points

A class consists of 50 women and 82 men. If a student is randomly

selected, what is the probability that the student is a woman?

A. 32/132

B. 27/66

C. 50/132

D. 82/132

Question 2 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.

Question 3 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 4 of 40

2.5/ 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

Based on meteorological records, the probability that it will snow in a certain town on January 1st is 0.413. Find the probability that in a given year it will not snow on January 1st in that town.

A. 0.345

B. 0.425

C. 0.587

D. 0.592

Question 6 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 7 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 8 of 40

0.0/ 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 9 of 40

2.5/ 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 10 of 40

0.0/ 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 that at least two heads occur consecutively?

A. 1/8

B. 3/8

C. 5/8

D. 6/8

Question 11 of 40

2.5/ 2.5 Points

The distribution of B.A. degrees conferred by a local college is listed below, by major.

Major Frequency

English 2073

Mathematics 2164

Chemistry 318

Physics 856

Liberal Arts 1358

Business 1676

Engineering 868

9313

What is the probability that a randomly selected degree is not in Business?

A. 0.7800

B. 0.8200

C. 0.8300

D. 0.9200

Question 12 of 40

2.5/ 2.5 Points

Suppose you pay $1.00 to roll a fair die with the understanding that you will get back $3.00 for rolling a 5 or a 2, nothing otherwise. What is your expected value?

A. $1.00

B. $0.00

C. $3.00

D. −$1.00

Question 13 of 40

2.5/ 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 14 of 40

2.5/ 2.5 Points

A committee of three people is to be formed. The three people will be selected from a list of five possible committee members. A simple random sample of three people is taken, without replacement, from the group of five people. Using the letters A, B, C, D, E to represent the five people, list the possible samples of size three and use your list to determine the probability that B is included in the sample. (Hint: There are 10 possible samples.)

A. 0.6

B. 0.4

C. 0.7

D. 0.8

Question 15 of 40

0.0/ 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 16 of 40

2.5/ 2.5 Points

A die with 12 sides is rolled. What is the probability of rolling a number less than 11? Is this the same as rolling a total less than 11 with two six-sided dice? Explain.

A. 2/6

B. 3/6

C. 4/6

D. 5/6

Question 17 of 40

0.0/ 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 18 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 19 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 20 of 40

2.5/ 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.

Part 2 of 2 - 12.5/ 50.0 Points

Question 21 of 40

0.0/ 2.5 Points

Monthly incomes of employees at a particular company have a mean of $5954. The distribution of sample means for samples of size 70 is normal with a mean of $5954 and a standard deviation of $259. Suppose you take a sample of size 70 employees from the company and find that their mean monthly income is $5747. How many standard deviations is the sample mean from the mean of the sampling distribution?

A. 0.8 standard deviations above the mean

B. 0.8 standard deviations below the mean

C. 7.3 standard deviations below the mean

D. 207 standard deviations below the mean

Question 22 of 40

0.0/ 2.5 Points

A random sample of 30 households was selected from a particular neighborhood. The number of cars for each household is shown below. Estimate the mean number of cars per household for the population of households in this neighborhood. Give the 95% confidence interval.

A. 1.14 to 1.88

B. 1.12 to 1.88

C. 1.12 to 1.98

D. 1.14 to 1.98

Question 23 of 40

0.0/ 2.5 Points

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

A. A

B. B

C. C

D. All the lines are equally good

Question 24 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.

A. 8.8

B. 6.2

C. 8.2

D. None of the values are correct

Question 25 of 40

0.0/ 2.5 Points

Select the best fit line on the scatter diagram below.

A. A

B. B

C. C

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

Question 26 of 40

0.0/ 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.

A. 5%

B. 10%

C. 95%

D. 90%

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

0.0/ 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 29 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 30 of 40

0.0/ 2.5 Points

Among a random sample of 500 college students, the mean number of hours worked per week at non-college related jobs is 14.6. This mean lies 0.4 standard deviations below the mean of the sampling distribution. If a second sample of 500 students is selected, what is the probability that for the second sample, the mean number of hours worked will be less than 14.6?

A. 0.5

B. 0.6179

C. 0.6554

D. 0.3446

Question 31 of 40

2.5/ 2.5 Points

Select the best fit line on the scatter diagram below.

A. A

B. B

C. C

D. All of the lines are equally good

Question 32 of 40

2.5/ 2.5 Points

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

A. -0.9

B. 0.9

C. 0.5

D. -0.5

Question 33 of 40

0.0/ 2.5 Points

A researcher wishes to estimate the mean amount of money spent per month on food by households in a certain neighborhood. She desires a margin of error of $30. Past studies suggest that a population standard deviation of $248 is reasonable. Estimate the minimum sample size needed to estimate the population mean with the stated accuracy.

A. 274

B. 284

C. 264

D. 272

Question 34 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 35 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 36 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.

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 37 of 40

2.5/ 2.5 Points

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

A. 0.60

B. -0.97

C. 0.10

D. -0.60

Question 38 of 40

0.0/ 2.5 Points

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

A.

B.

C.

D.

Question 39 of 40

2.5/ 2.5 Points

Of the 6796 students in one school district, 1537 cannot read up to grade level. Among a sample of 812 of the students from this school district, 211 cannot read up to grade level. Find the sample proportion of students who cannot read up to grade level.

A. 0.14

B. 0.26

C. 211

D. 0.23

Question 40 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. Determine the amount of variation in the number of cars not explained by the variation time after school.

A. 55%

B. 70%

C. 30%

D. 45%