stats mcq question

Part 1 of 9 -



Question 1 of 25 1.0 Points

Which of the following are the three most common measures of central location?
A.Mean, median, and variance
B.Mean, median, and standard deviation
C.Mean, variance, and standard deviation
D.Mean, median, and mode

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Part 2 of 9 -



Question 2 of 25 1.0 Points

The table below shows the preferences for elective courses of students who are undecided about their majors.

Philosophy Digital Art Film Studies
Male 9 16 22
Female 6 18 14

What is the probability of randomly selecting a student who is female or prefers Digital Art?


A.21.2%
B.84.7%
C.46.2%
D.63.5%

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Question 3 of 25 1.0 Points

If two events are mutually exclusive, what is the probability that both occur at the same time?
A.0.00
B.0.50
C.1.00
D.Cannot be determined from the information given.

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Part 3 of 9 -



Question 4 of 25 1.0 Points

A die is rolled 360 times. Find the standard deviation for the number of 3s that will be rolled.
A.60
B.50
C.7.1
D.5.9

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Question 5 of 25 1.0 Points

Suppose that 50 identical batteries are being tested. After 8 hours of continuous use, assume that a given battery is still operating with a probability of 0.70 and has failed with a probability of 0.30.

What is the probability that greater than 30 batteries will last at least 8 hours?
A.0.0848
B.0.8594
C.0.9522
D.0.9152

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Question 6 of 25 1.0 Points

If a student randomly guesses at 20 multiple-choice questions, find the probability that the student gets exactly four correct. Each question has four possible choices.

A.0.19
B.0.17
C.0.08
D.0.23

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Part 4 of 9 -



Question 7 of 25 1.0 Points

If the value of the standard normal random variable Z is positive, then the original score is where in relationship to the mean?
A.equal to the mean
B.to the left of the mean
C.to the right of the mean
D.one standard deviation higher than the mean

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Question 8 of 25 1.0 Points

One reason for standardizing random variables is to measure variables with:
A.dissimilar means and similar standard deviations in like terms
B.different means and standard deviations on a non-standard scale
C.different means and standard deviations on a single scale
D.similar means and standard deviations on two scales

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Question 9 of 25 1.0 Points

In a normal distribution, changing the standard deviation:
A.shifts the curve left or right
B.splits the distribution to two curves
C.makes the curve more or less spread out
D.makes the curve more robust

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Question 10 of 25 1.0 Points

The mean of a probability distribution can be:
A.a positive number
B.a negative number
C.zero
D.all of the above

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Question 11 of 25 1.0 Points

Given that the random variable X is normally distributed with a mean of 80 and a standard deviation of 10, P(85 < X < 90) is
A.0.1915
B.0.3413
C.0.5328
D.0.1498

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Question 12 of 25 1.0 Points

The normal distribution is:
A.a binomial distribution with only one parameter
B.a density function of a discrete random variable
C.a discrete distribution
D.the single most important distribution in statistics

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Part 5 of 9 -



Question 13 of 25 1.0 Points

Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000), "E" or "e" (used in scientific notation). NOTE: For scientific notation, a period MUST be used as the decimal point marker.
Complex numbers should be in the form (a + bi) where "a" and "b" need to have explicitly stated values.
For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not.

The histogram below represents scores achieved by 250 job applicants on a personality profile.

The histogram below represents scores achieved by 250 job applicants on a personality profile.


How many job applicants scored between 10 and 30? Place your answer in the blank. Do not use any stray symbols. For example, 123 would be a legitimate answer.




Part 6 of 9 -



Question 14 of 25 1.0 Points

Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000), "E" or "e" (used in scientific notation). NOTE: For scientific notation, a period MUST be used as the decimal point marker.
Complex numbers should be in the form (a + bi) where "a" and "b" need to have explicitly stated values.
For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not.

Suppose that the probability that a new medication will cause a bad side effect is 0.03. If this medication is given to 150 people, what is the probability that more than three of them will experience a bad side effect? Place your answer, rounded to 4 decimal places, in the blank. For example, 0.1776 would be a legitimate answer.


Question 15 of 25 1.0 Points

Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000), "E" or "e" (used in scientific notation). NOTE: For scientific notation, a period MUST be used as the decimal point marker.
Complex numbers should be in the form (a + bi) where "a" and "b" need to have explicitly stated values.
For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not.

A school determines that the number of children X in the families who attend the school follows the distribution below:

Number of children X 1 2 3 4 5
Probability P(X) 0.20 0.35 0.25 0.15 0.05

What is the mean number of children per family? Round your answer to one decimal place as necessary. For example, 4.5 would be a legitimate entry.

Answer:



Part 7 of 9 -



Question 16 of 25 1.0 Points

Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000), "E" or "e" (used in scientific notation). NOTE: For scientific notation, a period MUST be used as the decimal point marker.
Complex numbers should be in the form (a + bi) where "a" and "b" need to have explicitly stated values.
For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not.


According to an Internet posting, 80% of adults enjoy drinking beer. If a group of 3 adults is selected at random, find the probability that none of them enjoy drinking beer.

Place your answer, rounded to three decimal places, in the blank. When entering your answer do not use any labels or symbols other than a decimal point. Simply provide the numerical value. For example, 0.123 would be a legitimate entry.


Question 17 of 25 1.0 Points

Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000), "E" or "e" (used in scientific notation). NOTE: For scientific notation, a period MUST be used as the decimal point marker.
Complex numbers should be in the form (a + bi) where "a" and "b" need to have explicitly stated values.
For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not.

A restaurant menu has a price-fixed complete dinner that consists of an appetizer, entrée, beverage, and dessert. You have a choice of five appetizers, ten entrees, three beverages, and six desserts. How many possible complete dinners are possible? Place your answer, as a whole number—no decimal places—in the blank. For example 176 would be a legitimate entry



Part 8 of 9 -



Question 18 of 25 1.0 Points

Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000), "E" or "e" (used in scientific notation). NOTE: For scientific notation, a period MUST be used as the decimal point marker.
Complex numbers should be in the form (a + bi) where "a" and "b" need to have explicitly stated values.
For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not.

Scores on a mathematics examination appear to follow a normal distribution with mean of 65 and standard deviation of 15. The instructor wishes to give a grade of “C” to students scoring between the 60th and 70th percentiles on the exam.

What score represents the 70th percentile score on the mathematics exam? Place your answer in the blank, rounded to a whole number. For example, 62 would be a legitimate entry.


Question 19 of 25 1.0 Points

Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000), "E" or "e" (used in scientific notation). NOTE: For scientific notation, a period MUST be used as the decimal point marker.
Complex numbers should be in the form (a + bi) where "a" and "b" need to have explicitly stated values.
For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not.

A Wendy’s fast-food restaurant sells hamburgers and chicken sandwiches. On a typical weekday, the demand for hamburgers is normally distributed with a mean of 450 and standard deviation of 80 and the demand for chicken sandwiches is normally distributed with a mean of 120 and standard deviation of 30.

How many hamburgers must the restaurant stock to be 99% sure of not running out on a given day? Place you answer, rounded to the nearest whole number in the blank. For example, 345 would be a legitimate entry.


Question 20 of 25 1.0 Points

Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000), "E" or "e" (used in scientific notation). NOTE: For scientific notation, a period MUST be used as the decimal point marker.
Complex numbers should be in the form (a + bi) where "a" and "b" need to have explicitly stated values.
For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not.

A popular retail store knows that the purchase amounts by its customers is a random variable that follows a normal distribution with a mean of $30 and a standard deviation of $9.

What are the two dollar amounts, equidistant from the mean of $30, such that 98% of all customer purchases are between these values? Place your answers in the blanks provided. Do not include a dollar sign. For example, 14.25 would be a legitimate entry.

Lower value
Upper value


Question 21 of 25 1.0 Points

Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000), "E" or "e" (used in scientific notation). NOTE: For scientific notation, a period MUST be used as the decimal point marker.
Complex numbers should be in the form (a + bi) where "a" and "b" need to have explicitly stated values.
For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not.

A popular retail store knows that the purchase amounts by its customers is a random variable that follows a normal distribution with a mean of $30 and a standard deviation of $9.

What is the probability that a randomly selected customer will spend $20 or more at this store? Place your answer, rounded to 4 decimal places, in the blank. For example, 0.3456 would be a legitimate entry.


Question 22 of 25 1.0 Points

Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000), "E" or "e" (used in scientific notation). NOTE: For scientific notation, a period MUST be used as the decimal point marker.
Complex numbers should be in the form (a + bi) where "a" and "b" need to have explicitly stated values.
For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not.

Mrs. Smith's reading class can read a mean of 175 words per minute with a standard deviation of 20 words per minute. The top 3% of the class is to receive a special award. Assuming that the distribution of words read per minute are normally distributed, what is the minimum number of words per minute a student would have to read in order to get the award? Place your answer, rounded to the nearest whole number, in the blank. When entering your answer do not use any labels or symbols. Simply provide the numerical value. For example, 123 would be a legitimate entry.


Question 23 of 25 1.0 Points

Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000), "E" or "e" (used in scientific notation). NOTE: For scientific notation, a period MUST be used as the decimal point marker.
Complex numbers should be in the form (a + bi) where "a" and "b" need to have explicitly stated values.
For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not.

Scores on a mathematics examination appear to follow a normal distribution with mean of 65 and standard deviation of 15. The instructor wishes to give a grade of “C” to students scoring between the 60th and 70th percentiles on the exam.

What score represents the 60th percentile score on the mathematics exam? Place your answer in the blank, rounded to a whole number. For example, 62 would be a legitimate entry.



Part 9 of 9 -



Question 24 of 25 1.0 Points

Using the standard normal curve, the Z- score representing the 10th percentile is 1.28. True
False

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Question 25 of 25 1.0 Points

The left half under the normal curve is slightly smaller than the right half. True
False