Sammy and Sally each carry a bag containing a banana, a chocolate bar
Sammy and Sally each carry a bag containing a banana, a chocolate bar
Subject: Mathematics / Statistics
Question
Question 1 of 40
5.0 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 2 of 40
5.0 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 3 of 40
5.0 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 4 of 40
5.0 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 5 of 40
5.0 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 7 of 40
5.0 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 8 of 40
5.0 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 9 of 40
5.0 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 10 of 40
5.0 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 11 of 40
5.0 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 12 of 40
5.0 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 13 of 40
5.0 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 14 of 40
5.0 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 15 of 40
5.0 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 16 of 40
5.0 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 17 of 40
5.0 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 18 of 40
5.0 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 19 of 40
5.0 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 20 of 40
5.0 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 21 of 40
5.0 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 22 of 40
5.0 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%
Question 23 of 40
5.0 Points
Suggest the cause of the correlation among the data.
The graph shows strength of coffee (y) and number of scoops used to make 10 cups of coffee (x). Identify the probable cause of the correlation.
A.
The variation in the x variable is a direct cause of the variation in
the y variable.
B. There is no correlation between the variables.
C. The correlation is due to a common underlying cause.
D. The correlation between the variables is coincidental.
Question 24 of 40
5.0 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 25 of 40
5.0 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 26 of 40
5.0 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 27 of 40
5.0 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 28 of 40
5.0 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 29 of 40
5.0 Points
Select the best estimate of the correlation coefficient for the data depicted in the scatter diagram.
A. -0.9
B. -0.1
C. -0.5
D. 0.9
Question 30 of 40
5.0 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 31 of 40
5.0 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.
A. 7.0
B. 6.0
C. 8.0
D. 3.5
Question 32 of 40
5.0 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 33 of 40
5.0 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 34 of 40
5.0 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 35 of 40
5.0 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 36 of 40
5.0 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 38 of 40
5.0 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 39 of 40
5.0 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 40 of 40
5.0 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
