Question 1

An advocacy group is investigating whether gender has an effect on job category in large investment firms.Given the results shown in the table below, which of the following statements is true about gender and job category?

A)Gender and job category are independent.
B)Gender and job category are not independent.
C)Gender and job category are mutually exclusive.
D)Gender and job category are independent and mutually exclusive.
E)There is not sufficient information to determine whether gender and job category are independent or mutually exclusive.

Accepted Answer

The answer of An advocacy group is investigating whether gender...

Question 2

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 64 and 88.
A)95%
B)68%
C)99.7%
D)81.5%
E)49.85%

Accepted Answer

The answer of Assume that a set of test scores...

Question 3

A survey of investors finds that 60% use a full service brokerage firm to invest in stocks, 30% trade stocks online and 24% do both.The probability that an investor selected at random uses a full service brokerage firm or trades stocks online is ________________________ .
One line space needed
A)90%
B)66%
C)34%
D)54%
E)60%

Accepted Answer

The answer of A survey of investors finds that 60%...

Question 4

Suppose that a Normal model describes fuel economy (miles per gallon) for automobiles and that a Toyota Corolla has a standardized score (z-score) of +2.2.This means that Corollas ________________________ .
A)get 2.2 mpg more than the average car.
B)achieve fuel economy that is 2.2 standard deviations better than the average car.
C)get 2.2 miles per gallon.
D)have a standard deviation of 2.2 mpg.
E)get 2.2 times the gas mileage of the average car.

Accepted Answer

A z-score of +2.2 indicates that the Toyota Corolla's fuel economy is 2.2 standard deviations above the mean, not the other metrics mentioned.

Question 5

A men's clothing store has determined the following probability distribution for the number of special size orders placed per month.Based on this distribution, the standard deviation in the number of special size orders placed per month is ________________________ .

A)43.56
B)6.6
C)15.345
D)4.9
E)3.88

Accepted Answer

The answer of A men's clothing store has determined the...

Question 6

A manufacturing process has a 70% yield, meaning that 70% of the products are acceptable and 30% are defective.If three of the products are randomly selected, find the probability that all of them are acceptable.
A)0.429
B)0.027
C)0.343
D)2.1
E)0.7

Accepted Answer

The probability that all three products are acceptable is the product of the probability of each one being acceptable: $0.7 \times 0.7 \times 0.7 = 0.343$.

Question 7

The weather reporter predicts that there is a 20% chance of snow tomorrow for a certain region.What is meant by this phrase?
One line space needed
A)Snow occurs 20% of the time in this region.
B)In circumstances "like this," snow occurs 20% of the time.
C)The occurrence of snow is "truly random" and will occur 20% of the time.
D)It will rain 20% of the day tomorrow.
E)20% of the time it snows on this date.

Accepted Answer

This phrase means that based on historical weather data and current conditions, when similar weather patterns have occurred in the past, snow has fallen 20% of the time. It's a probabilistic forecast based on patterns and models, not a statement about the frequency of snow on specific dates or a guarantee of randomness.

Question 8

Which of those variables about German Shepherds is most likely to be described by a Normal model?
A)weight
B)breed
C)number of days housed
D)veterinary costs
E)age

Accepted Answer

Weight is a continuous variable that often follows a normal distribution in a population, making it suitable for a Normal model.

Question 9

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 less than 56.
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 68% of the data within a normal distribution falls within one standard deviation of the mean, 95% falls within two standard deviations, and 99.7% falls within three standard deviations. A score of 56 is two standard deviations below the mean (72 - 2*8 = 56). Therefore, 2.5% of the scores are less than 56, as the lower tail (below -2 standard deviations) accounts for half of the remaining 5% (100% - 95% = 5%) not within two standard deviations of the mean.

Question 10

An advocacy group is investigating whether gender has an effect on job category in large investment firms.She surveyed a sample of firms with the following results:

What is the probability that a randomly selected employee's job category is executive / managerial given that she is female?
One line space needed
A)0.13
B)0.20
C)0.80
D)0.05
E)0.45

Accepted Answer

The answer of An advocacy group is investigating whether gender...

Question 11

Referring to question #12, approximately how heavy would a male Golden Retriever be in order to be in the heaviest 5% of such dogs?
A)65 lbs.
B)68 lbs.
C)84 lbs.
D)75 lbs.
E)82 lbs.

Accepted Answer

The heaviest 5% of male Golden Retrievers would be those at the top end of the weight range. 82 lbs is a reasonable estimate for a weight that would place a dog in the top 5% of its breed.

Question 12

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 meat, what is the probability that the student is a junior?
One line space needed
A)0.179
B)0.14
C)0.059
D)0.209
E)0.289

Accepted Answer

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

Question 13

A researcher notes that the weight of a male Golden Retriever is approximately normally distributed with a mean of 70 lbs.and a standard deviation of 7.5 lbs.What percentage of these dogs weigh less than 65 lbs?
One line space needed
A)33%
B)75%
C)66.7%
D)25%
E)5%

Accepted Answer

The answer of A researcher notes that the weight of...

Question 14

The number of claims for lost luggage in a small city airport averages nine per day.Assuming the Poisson distribution, what is the probability that there will be fewer than 3 claims on any given day?
One line space needed
A)0.0150
B)0.0212
C)0.0062
D)0.0337
E)0.5000

Accepted Answer

The answer of The number of claims for lost luggage...

Question 15

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.Suppose a random sample of 25 ordering processes is selected.What is the probability that the sample mean will be less than 7.5 minutes?
A)0.3944
B)0.1056
C)0.2114
D)0.4013
E)0.8944

Accepted Answer

The standard error of the mean is 2/sqrt(25) = 0.4. The z-score for 7.5 is (7.5-8)/0.4 = -1.25. Using the standard normal distribution table, the probability of a z-score being less than -1.25 is approximately 0.1056.

Question 16

In a blood testing procedure, blood samples from 5 people are combined into one mixture.The mixture will only test negative if all the individual samples are negative.If the probability that an individual sample tests positive is 0.12, what is the probability that the mixture will test positive?
One line space needed
A)0.0000249
B)0.528
C)0.0144
D)0.472
E)1.00

Accepted Answer

The answer of In a blood testing procedure, blood samples...

Question 17

A North American mole weighs an average of 3.5 oz.with a standard deviation of 0.9 oz.and a distribution that is approximately normal.In what percentile is the weight of a mole that weighs 4.25 oz.?
A)20.2%
B)79.8%
C)6.022%
D)17.7%
E)83.3%

Accepted Answer

To find the percentile of a mole that weighs 4.25 oz., we first calculate its z-score using the formula z = (X - μ) / σ, where X is the value (4.25 oz.), μ is the mean (3.5 oz.), and σ is the standard deviation (0.9 oz.). This gives us z = (4.25 - 3.5) / 0.9 ≈ 0.833. Looking up this z-score in a standard normal distribution table or using a calculator, we find that it corresponds to a percentile of approximately 79.8%, which is option B.

Question 18

In a particular production process, drying times for newly pained parts are uniformly distributed between 2 and 8 minutes.The probability that a part dries in less than 6 minutes is ________________________ .
On
A)2/6
B)2/8
C)3/6
D)4/6
E)4/8

Accepted Answer

The drying time is uniformly distributed between 2 and 8 minutes, making the total interval 6 minutes long. To find the probability of a part drying in less than 6 minutes, we calculate the length of the interval from 2 to 6 minutes, which is 4 minutes. Therefore, the probability is 4 minutes out of the total 6 minutes, or 4/6.

Question 19

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 meat | student is junior).
One line space needed
A)0.301
B)0.186
C)0.062
D)0.239
E)0.16

Accepted Answer

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

Question 20

Light bulbs are measured in lumens (light output), watts (energy used), and hours (life).A standard white light bulb has a mean life of 675 hours and a standard deviation of 50 hours.A soft white light bulb has a mean life of 700 hours and a standard deviation of 35 hours.At a local science competition, both light bulbs lasted 750 hours.Which light bulb's life span was better?
A)The soft white light bulb because it is 7% beyond the mean.
B)The standard white light bulb because it is 75 hours beyond the mean.
C)The standard white light bulb because it is 11% beyond the mean.
D)The standard light bulb because it lasted 1.5 standard deviations above the mean life.
E)The soft white light bulb because it is 50 hours beyond the mean.

Accepted Answer

The standard white light bulb's performance is better relative to its mean and standard deviation. It lasted 750 hours, which is 75 hours beyond its mean of 675 hours. Given its standard deviation of 50 hours, this is 1.5 standard deviations above the mean (75/50 = 1.5). This is a more significant deviation from the mean compared to the soft white light bulb, which lasted 50 hours beyond its mean of 700 hours, or approximately 1.43 standard deviations above the mean (50/35 ≈ 1.43).

Quiz 26: Statistics and Data Analysis

An advocacy group is investigating whether gender has an effect on job category in large investment firms.Given the results shown in the table below, which of the following statements is true about gender and job category?

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 64 and 88.

A survey of investors finds that 60% use a full service brokerage firm to invest in stocks, 30% trade stocks online and 24% do both.The probability that an investor selected at random uses a full service brokerage firm or trades stocks online is ________________________ . One line space needed

Suppose that a Normal model describes fuel economy (miles per gallon) for automobiles and that a Toyota Corolla has a standardized score (z-score) of +2.2.This means that Corollas ________________________ .

A men's clothing store has determined the following probability distribution for the number of special size orders placed per month.Based on this distribution, the standard deviation in the number of special size orders placed per month is ________________________ .

A manufacturing process has a 70% yield, meaning that 70% of the products are acceptable and 30% are defective.If three of the products are randomly selected, find the probability that all of them are acceptable.

The weather reporter predicts that there is a 20% chance of snow tomorrow for a certain region.What is meant by this phrase? One line space needed

Which of those variables about German Shepherds is most likely to be described by a Normal model?

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 less than 56.

Referring to question #12, approximately how heavy would a male Golden Retriever be in order to be in the heaviest 5% of such dogs?

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 meat, what is the probability that the student is a junior? One line space needed

A researcher notes that the weight of a male Golden Retriever is approximately normally distributed with a mean of 70 lbs.and a standard deviation of 7.5 lbs.What percentage of these dogs weigh less than 65 lbs? One line space needed

The number of claims for lost luggage in a small city airport averages nine per day.Assuming the Poisson distribution, what is the probability that there will be fewer than 3 claims on any given day? One line space needed

A North American mole weighs an average of 3.5 oz.with a standard deviation of 0.9 oz.and a distribution that is approximately normal.In what percentile is the weight of a mole that weighs 4.25 oz.?

In a particular production process, drying times for newly pained parts are uniformly distributed between 2 and 8 minutes.The probability that a part dries in less than 6 minutes is ________________________ . On

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 meat | student is junior) . One line space needed