Question 1

A government agency has 6000 employees.As an alternative to the traditional five day work week, employees were asked whether they preferred a four day work week (10 hours per day) or flexible hours.The table below shows the results by age category.Which of the following statements is true about work week preferences and age category?

A)Work week preferences are independent of age category.
B)Work week preferences are mutually exclusive.
C)Work week preferences are not independent of age category.
D)Work week preferences are independent and mutually exclusive.
E)There is insufficient information to determine whether work week preferences and age category are independent or mutually exclusive.

Accepted Answer

The answer of A government agency has 6000 employees.As an...

Question 2

College students were given three choices of pizza toppings and asked to choose one favorite.The following table shows the results.

Find P(favorite topping is veggie | student is junior or senior).
A)0.605
B)0.197
C)0.316
D)0.46
E)0.359

Accepted Answer

The answer of College students were given three choices of...

Question 3

One ball is removed from a bag containing 1 blue ball, 1 red ball, 1 yellow ball, and 1 green ball.Without returning the first ball to the bag a second ball is removed.Determine whether the events are disjoint, independent, complimentary, all or none of these.
A)Disjoint
B)Independent
C)Complimentary
D)All of these
E)None of these

Accepted Answer

The answer of One ball is removed from a bag...

Question 4

A manufacturer of cordless electric shavers sampled 13 from a day's production and found the mean time of continuous usage without recharging to be 410 minutes with a sample standard deviation of 30 minutes.We can assume that times are normally distributed.We wish to test if the true mean operating time without recharging is more than 400 minutes.The correct calculated value of the test statistic is ________________________ .
A)1.20
B)-0.333
C)-2.52
D)-1.20
E)2.79

Accepted Answer

The answer of A manufacturer of cordless electric shavers sampled...

Question 5

A government agency has 6000 employees.As an alternative to the traditional five day work week, employees were asked whether they preferred a four day work week (10 hours per day) or flexible hours.The table below shows the results by age category.What is the probability that an employee at this government agency prefers a four day work week?

A)0.54
B)0.15
C)0.50
D)0.35
E)0.65

Accepted Answer

The answer of A government agency has 6000 employees.As an...

Question 6

As a result of the financial crisis on Wall Street in September 2008 that required federal government intervention, a survey showed that 40% of Americans reallocated their investments to reduce exposure to the stock market.What is the probability that out of 5 randomly selected Americans, none will have reallocated their investments in this way?
A)0.2592
B)0.8154
C)0.1699
D)0.0778
E)0.1234

Accepted Answer

The answer of As a result of the financial crisis...

Question 7

College students were given three choices of pizza toppings and asked to choose one favorite.The following table shows the results.

Given that a student's favorite topping is veggie, what is the probability that the student is a junior or a senior?
A)0.208.
B)0.41.
C)0.631.
D)0.385.
E)0.380.

Accepted Answer

The answer of College students were given three choices of...

Question 8

A Normal probability plot of the weights of individuals signed up for a popular diet program is shown below.The best description of the plot is _______________________ .

A)The distribution is fairly symmetric.
B)The distribution is right skewed and nonlinear.
C)The kink in the bend success values that don't continue the skewness consistently.
D)The distribution is left skewed and nonlinear.
E)B and C are correct.

Accepted Answer

The answer of A Normal probability plot of the weights...

Question 9

IT staff for a large corporation has developed the following probability distribution for the number of calls requiring troubleshooting problems per day.Based on the distribution, the expected number of calls per day is

A)2.77
B)1.56
C)1.21
D)1.31
E)1

Accepted Answer

The answer of IT staff for a large corporation has...

Question 10

After the financial crisis of 2007/2008, the Dow Jones Industrial Average (DJIA) improved from a low of 7278 on March 20, 2009, to new records just a few years later.On August 8, 2011, the Dow dropped 634.8 points.A histogram of day-to-day changes in the DJIA looked like the histogram below.An accurate description of the distribution of changes in the DJIA is

A)The distribution is fairly symmetric.
B)The distribution is somewhat left skewed with a number of low outliers.
C)A normal probability plot would add information about the normality of the data set.
D)Both A and C
E)Both B and C

Accepted Answer

The answer of After the financial crisis of 2007/2008, the...

Question 11

Chris Columbus is responsible for controlling inventory levels for four types of sailboats sold by his company.Chris takes a sample of 48 boats sold over the past several months to determine if demand is the same for each type.His results are as follows:

The calculated value of the Chi Square statistic is ________________________ .
A)7.815
B)1.17
C)22.35
D)-1.17
E)12.56

Accepted Answer

The answer of Chris Columbus is responsible for controlling inventory...

Question 12

Assume that a set of test scores in an Introduction to Finance class is normally distributed with a mean of 72 and a standard deviation of 8.Use the 68-95-99.7 rule to find the percentage of scores greater than 88.
A)0.15%
B)0.3%
C)2.5%
D)5%
E)95%

Accepted Answer

According to the 68-95-99.7 rule (or the empirical rule), approximately 95% of the data in a normal distribution falls within two standard deviations of the mean. Since the mean is 72 and the standard deviation is 8, two standard deviations above the mean is 72 + 2(8) = 88. Therefore, 95% of the scores are below 88, leaving 5% of the scores above 88. However, this 5% is split between the two tails of the distribution, so only 2.5% of the scores are greater than 88.

Question 13

A manufacturer of cordless electric shavers sampled 13 from a day's production and found the mean time of continuous usage without recharging to be 410 minutes with a sample standard deviation of 30 minutes.We can assume that times are normally distributed.We wish to test if the true mean operating time without recharging is more than 400 minutes.The correct null and alternative hypotheses are ________________________ . A)H_{0 :}µ = 400; H_A : µ < 400 B)H_{0 :}µ = 400; H_A : µ > 400 C)H_{0 :}µ > 400; H_A : µ = 400 D)H_{0 :}µ < 400; H_A : µ = 400 E)H_{0 :}µ = 400; H_A : µ ≠ 400

Accepted Answer

The null hypothesis (H0) is a statement of no effect or no difference, and it is what we seek evidence against. Here, it is that the true mean operating time is 400 minutes (µ = 400). The alternative hypothesis (Ha) represents the outcome the test is trying to support, in this case, that the true mean operating time is more than 400 minutes (µ > 400).

Question 14

The residual, or the difference, between the observed frequency and the expected frequency is a reliable indicator.A standardized residual can also be computed for each cell.Which statements are true about standardized residuals?
A)Standardized residuals that have a positive value mean that the cell was over-represented in the actual sample, compared to the expected frequency.
B)The standardized residual can be compared against the critical z-value for your α level to determine significance.
C)Standardized residuals can be used to test the null hypothesis that the actual frequency equals the expected frequency for a specific cell versus the research hypothesis of a difference greater than zero.
D)Standardized residuals that have a negative value mean that the cell was under-represented in the actual sample, compared to the expected frequency.
E)All of the above.

Accepted Answer

All statements about standardized residuals are true. They indicate over-representation with positive values and under-representation with negative values, can be compared against critical z-values to determine significance, and are used to test hypotheses about frequency differences.

Question 15

In one city, 47.5% of adults are female, 10.2% of adults are left-handed, and 4.8% are females.For an adult selected at random from the city, let
F = event the person is female
L = event the person is left-handed.
Find P(F or L).Round approximations to three decimal places.
A)0.6245
B)0.679
C)0.482
D)0.577
E)0.529

Accepted Answer

The answer of In one city, 47.5% of adults are...

Question 16

A professor divided the students in her business class into three groups: those who have never taken a statistics class, those who have taken only one semester of a statistics class, and those who have taken two or more semesters of statistics.The professor randomly assigns students to groups of three to work on a project for the course.
If 65% of the students have never taken a statistics class, 15% have taken only one semester of a statistics class, and the rest have taken two or more semesters of statistics, what is the probability that the first groupmate you meet has studied at least two semesters of statistics?
A)0.20
B)0.15
C)0.80
D)0.85
E)0.35

Accepted Answer

20%The percentage of students who have taken two or more semesters of statistics is 100% - 65% - 15% = 20%.

Question 17

Assume that a set of test scores in an Introduction to Finance class is normally distributed with a mean of 72 and a standard deviation of 8.Use the 68-95-99.7 rule to find the percentage of scores between 80 and 96.
A)13.5%
B)15.85%
C)30.7%
D)2.5%
E)25.5%

Accepted Answer

According to the 68-95-99.7 rule, 68% of scores lie within one standard deviation (64 to 80), 95% within two (56 to 88), and 99.7% within three (48 to 96). Scores between 80 and 96 cover the range from one to three standard deviations above the mean, which is 13.5% (from 80 to 88) plus 2.35% (from 88 to 96), totaling 15.85%.

Question 18

Suppose the time it takes for a purchasing agent to complete an online ordering process is normally distributed with a mean of 8 minutes and a standard deviation of 2 minutes.What is the probability that it takes longer than 11 minutes for the purchasing agent to complete the process?
A)0.9332
B)0.4332
C)0.0668
D)0.5668
E)none of the above

Accepted Answer

To find the probability that it takes longer than 11 minutes, we calculate the Z-score for 11 minutes using the formula Z = (X - μ) / σ, where X is 11, μ is 8, and σ is 2. This gives us Z = (11 - 8) / 2 = 1.5. Looking up the Z-score of 1.5 in the standard normal distribution table, we find the area to the left of Z is approximately 0.9332. Since we want the area to the right (the probability of taking longer than 11 minutes), we subtract this from 1, giving 1 - 0.9332 = 0.0668.

Question 19

A publishing company conducted a survey of its readership and found that 60% subscribed to Food & Wine, 30% subscribed to Wine Spectator, and 25% subscribed to both.The probability that a reader does not subscribe to either is ________________________ .
GLOBAL : please provide space between every question and options
A)0.10
B)0.65
C)0.50
D)0.45
E)0.35

Accepted Answer

Using the principle of inclusion-exclusion, the probability that a reader subscribes to at least one magazine is 0.60 + 0.30 - 0.25 = 0.65. Therefore, the probability that a reader does not subscribe to either is 1 - 0.65 = 0.35.

Question 20

A survey revealed that 45% of people are entertained by reading books, 46% are entertained by watching TV, and 9% are entertained by both books and TV.What is the probability that a person will be entertained by either books or TV?
A)1.0
B)0.9
C)0.82
D)0.8
E)0.91

Accepted Answer

The probability of being entertained by either books or TV is calculated using the formula for the union of two events: P(A or B) = P(A) + P(B) - P(A and B). Here, P(A) = 0.45, P(B) = 0.46, and P(A and B) = 0.09. So, P(A or B) = 0.45 + 0.46 - 0.09 = 0.82.

Quiz 26: Statistics and Data Analysis

College students were given three choices of pizza toppings and asked to choose one favorite.The following table shows the results. Find P(favorite topping is veggie | student is junior or senior) .

One ball is removed from a bag containing 1 blue ball, 1 red ball, 1 yellow ball, and 1 green ball.Without returning the first ball to the bag a second ball is removed.Determine whether the events are disjoint, independent, complimentary, all or none of these.

College students were given three choices of pizza toppings and asked to choose one favorite.The following table shows the results. Given that a student's favorite topping is veggie, what is the probability that the student is a junior or a senior?

A Normal probability plot of the weights of individuals signed up for a popular diet program is shown below.The best description of the plot is _______________________ .

IT staff for a large corporation has developed the following probability distribution for the number of calls requiring troubleshooting problems per day.Based on the distribution, the expected number of calls per day is

Assume that a set of test scores in an Introduction to Finance class is normally distributed with a mean of 72 and a standard deviation of 8.Use the 68-95-99.7 rule to find the percentage of scores greater than 88.

The residual, or the difference, between the observed frequency and the expected frequency is a reliable indicator.A standardized residual can also be computed for each cell.Which statements are true about standardized residuals?

In one city, 47.5% of adults are female, 10.2% of adults are left-handed, and 4.8% are females.For an adult selected at random from the city, let F = event the person is female L = event the person is left-handed. Find P(F or L) .Round approximations to three decimal places.

Assume that a set of test scores in an Introduction to Finance class is normally distributed with a mean of 72 and a standard deviation of 8.Use the 68-95-99.7 rule to find the percentage of scores between 80 and 96.

Suppose the time it takes for a purchasing agent to complete an online ordering process is normally distributed with a mean of 8 minutes and a standard deviation of 2 minutes.What is the probability that it takes longer than 11 minutes for the purchasing agent to complete the process?

A survey revealed that 45% of people are entertained by reading books, 46% are entertained by watching TV, and 9% are entertained by both books and TV.What is the probability that a person will be entertained by either books or TV?