Question 1 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 2 of 40
2.5/ 2.5 Points
Suppose you have an extremely unfair die: The probability of a 6 is 3/8, and the probability of each other number is 1/8. If you toss the die 32 times, how many twos do you expect to see?
A. 2
B. 4
C. 3
D. 5
Question 3 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 4 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 5 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 6 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 7 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 8 of 40
0.0/ 2.5 Points
A study of 600 college students taking Statistics 101 revealed that 54 students received the grade of A. Typically 10% of the class gets an A. The difference between this group of students and the expected value is not significant at the 0.05 level. What does this mean in this case?
A. The probability that the difference occurred due to chance is less than 0.05.
B. The probability of getting an A is 10% and only 9% got an A in this study. The difference is less than 5% so it is not significant.
C. There is not enough information to make any conclusion.
D. The probability that the difference occurred due to chance is more than 0.05.
Question 9 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 10 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 11 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 12 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 13 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 14 of 40
2.5/ 2.5 Points
Suppose you have an extremely unfair coin: the probability of a head is 1/3 and the probability of a tail is 2/3. If you toss the coin 72 times, how many heads do you expect to see?
A. 12
B. 22
C. 24
D. 26
Question 15 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 16 of 40
2.5/ 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 17 of 40
0.0/ 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 18 of 40
0.0/ 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 19 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 20 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. 25/66
C. 50/132
D. 82/132
Question 22 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 23 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 25 of 40
2.5/ 2.5 Points
Among a random sample of 150 employees of a particular company, the mean commute distance is 29.6 miles. This mean lies 1.2 standard deviations above the mean of the sampling distribution. If a second sample of 150 employees is selected, what is the probability that for the second sample, the mean commute distance will be less than 29.6 miles?
A. 0.8849
B. 0.5
C. 0.1131
D. 0.1151
Question 27 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 28 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 31 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 36 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 39 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
