# Quiz on statistics :: 19 questions :

**QUESTIONS :**

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Question 1 of 20 1.0 Points

Numerical variables can be subdivided into which two types?

A.Cross-sectional and discrete

B.Diverse and categorical

C.Discrete and continuous

D.Nominal and progressive

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Question 2 of 20 1.0 Points

Which of the following statements is true regarding the data set 10, 10, 10, 10, and 10?

A.The range is zero

B.The standard deviation equals zero

C.The interquartile range equals zero

D.all of the above

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Question 3 of 20 1.0 Points

Which of the following correctly describes the relationship between a sample and a population?

A.A sample is a group of subjects selected from a population to be studied.

B.A sample is a group of populations that are subject to observation.

C.A population and a sample are not related.

D.A population is a group of samples that may or may not be included in a study

Question 4 of 20 1.0 Points

A histogram that has a single peak and looks approximately the same to the left and right of the peak is called:

A.balanced

B.proportional

C.bimodal

D.symmetric

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Question 5 of 20 1.0 Points

The amount of time needed to run the Boston marathon is an example of which type of variable?

A.qualitative

B.none of the above

C.discrete

D.continuous

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Question 6 of 20 1.0 Points

The length of the box in the boxplot portrays the

A.range

B.median

C.interquartile range

D.mean

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Question 7 of 20 1.0 Points

Suppose that a histogram of a data set is approximately symmetric and “bell shaped”. Approximately what percent of the observations are within one standard deviation of the mean?

A.68%

B.95%

C.50%

D.99.7%

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Question 8 of 20 1.0 Points

Which of the following statements are false?

A.A categorical variable is nominal if there is natural ordering of its possible values.

B.A variable is numerical if meaningful arithmetic can be performed on it.

C.Zip codes are usually treated as categorical variables, although they appear to be numerical.

D.All of the above

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Question 9 of 20 1.0 Points

Which of the following statements are false regarding a boxplot?

A.The height of the box has no significance.

B.The length of the box equals the range of the data.

C.Boxplots can be used to either describe a single variable in a data set or to compare two (or more) variables

D.The right and left of the box are the third and first quartiles

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Question 10 of 20 1.0 Points

The total frequency of the data whose ogive is shown below is approximately

A.18

B.90

C.34

D.12

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Question 11 of 20 1.0 Points

Gender and State are examples of which type of data?

A.Categorical data

B.Discrete data

C.Ordinal data

D.Continuous data

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Question 12 of 20 1.0 Points

For a boxplot, the vertical line inside the box indicates the location of the

A.inter quartile range

B.median

C.mode

D.mean

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Question 13 of 20 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 student scored 84 points on a test where the mean score was 79 and the standard deviation was 4. Find the student’s z score, rounded to 2 decimal places, and place it in the blank.

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Question 14 of 20 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 sample of 150 students at a State University was taken after the final business statistics exam to ask them whether they went partying the weekend before the final or spent the weekend studying, and whether they did well or poorly on the final. The following table contains the result.

Did Well in Exam Did Poorly in Exam

Studying for Exam 60 15

Went Partying 22 53

Of those in the sample who did well on the final exam, what percentage of them went partying the weekend before the exam? Place your answer in the blank, rounded to 2 decimal places. Do not use a percentage sign (%). For example, 44.44 would be a legitimate answer.

Question 16 of 20 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 statistics professor has just given a final examination in his statistical inference course. He is particularly interested in learning how his class of 40 students performed on this exam. The scores are shown below.

77 81 74 77 79 73 80 85 86 73

83 84 81 73 75 91 76 77 95 76

90 85 92 84 81 64 75 90 78 78

82 78 86 86 82 70 76 78 72 93

What is the mean score on this exam? Place your answer, rounded to two decimal places in the blank. For example, 65.78 would be a legitimate entry.

Question 17 of 20 1.0 Points

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 sample of 150 students at a State University was taken after the final business statistics exam to ask them whether they went partying the weekend before the final or spent the weekend studying, and whether they did well or poorly on the final. The following table contains the result.

Did Well on Exam Did Poorly on Exam

Studying for Exam 60 15

Went Partying 22 53

If the sample is a good representation of the population, what percentage of those who did poorly on the final exam should we expect to have spent the weekend studying? Place your answer in the blank, rounded to 2 decimal places. Do not use a percentage sign (%). For example, 44.44 would be a legitmate answer.

Question 18 of 20 1.0 Points

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 following data represent the number of children in a sample of 10 families from Chicago: 4, 2, 1, 1, 5, 3, 0, 1, 0, and 2.

Compute the variance of the data. Place your answer, rounded to two decimal places, in the blank. For example, 3.45 would be a legitimate entry.

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Question 19 of 20 1.0 Points

Age, height, and weight are examples of numerical data.

True

False

Question 20 of 20 1.0 Points

Phone numbers, Social Security numbers, and zip codes are examples of numerical variables

True

False