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QNT 275 Week 2 Practice: Connect Knowledge Check

Complete the Week 2 Knowledge Check in Connect.

In a statistics class, the following 10 scores were randomly selected: 74, 73, 77, 77, 71, 68, 65, 77, 67, 66.

What is the median?

73.0

77.0

71.5

71.0

72.0

Quality control is an important issue at ACME Company, which manufactures light bulbs. Totest the life-hours of their light bulbs, they randomly sampled nine light bulbs and measured how many hours they lasted: 378, 361, 350, 375, 200, 391, 375, 368, 321.

What is the mode?

368

200

375

389.9

346.6

In a hearing test, subjects estimate the loudness (in decibels) of a sound, and the results are: 68, 67, 70, 71, 68, 75, 68, 62, 80, 73, 68.

What is the mode?

71

68

75

80

70

In a hearing test, subjects estimate the loudness (in decibels) of a sound, and the results are: 68, 67, 70, 71, 68, 75, 68, 62, 80, 73, 68.

What is the median?

70

80

71

75

68

In a hearing test, subjects estimate the loudness (in decibels) of a sound, and the results are: 68, 67, 70, 71, 68, 75, 68, 62, 80, 73, 68.

What is the mean?

70

80

75

71

68

Which of the following is not a graphical tool for descriptive analytics (dashboards)?

scatter plot

sparkline

gauge

treemap

bullet graph

When establishing the classes for a frequency table, it is generally agreed that the more classes you use the better your frequency table will be.

True

False

Which percentile describes the first quartile, Q1?

50th

100th

75th

25th

In a statistics class, 10 scores were randomly selected with the following results: 74, 73, 77, 77, 71, 68, 65, 77, 67, 66.

What is the IQR?

5.00

12.00

10

11.00

5.25

The company financial officer was interested in the average cost of PCs that had been purchased in the past six months. She took a random sample of the price of 10 computers, with the following results.

$3,250, $1,127, $2,995, $3,250, $3,445, $3,449, $1,482, $6,120, $3,009, $4,000

What is the IQR?

454

255

6120

681

1362

The stem-and-leaf display is advantageous because it allows us to actually see the measurements in the data set.

True

False

In a statistics class, the following 10 scores were randomly selected: 74, 73, 77, 77, 71, 68, 65, 77, 67, 66.

What is the mode?

71.5

72.0

77.0

73.0

71.0

The median is the value below which and above which approximately 50 percent of the measurements lie.

True

False

A bar chart is a graphic that can be used to depict qualitative data.

True

False

A correlation coefficient close to −1 says x and y are highly related.

True

False

The local amusement park was interested in the average wait time at their most popular roller coaster at the peak park time (2 p.m.). They selected 13 patrons and had them get in line between 2 and 3 p.m. Each was given a stopwatch to record the time they spent in line. The times recorded were as follows (in minutes): 118, 124, 108, 116, 99, 120, 148, 118, 119, 121, 45, 130, 118.

What is the mode?

115.5

45

114.15

118

148

Quality control is an important issue at ACME Company, which manufactures light bulbs. To test the life-hours of their light bulbs, they randomly sampled nine light bulbs and measured how many hours they lasted (mean = 346.6).

378, 361, 350, 375, 200, 391, 375, 368, 321

What is the range?

3424.3

58.5

191

342.43

10,609

In the least squares line, ___________ is defined as rise/run.

slope

correlation coefficient

predicted value of y

y-intercept

Quality control is an important issue at ACME Company, which manufactures light bulbs. Totest the life-hours of their light bulbs, they randomly sampled nine light bulbs and measured how many hours they lasted: 378, 361, 350, 375, 200, 391, 375, 368, 321.

What is the mode?

368

200

346.6

375

389.9

________ can be used to study the relationship between two variables.

Dot plots

Frequency tables

Cumulative frequency distributions

Cross-tabulation tables

The local amusement park was interested in the average wait time at their most popular roller coaster at the peak park time (2 p.m.). They selected 13 patrons and had them get in line between 2 and 3 p.m. Each was given a stopwatch to record the time they spent in line. The times recorded were as follows (in minutes;mean = 114.15):

118, 124, 108, 116, 99, 120, 148, 118, 119, 121, 45, 130, 118.

What is the range?

103

115

557.97

23.62

128.8

In a statistics class, 10 scores were randomly selected with the following results (mean = 71.5): 74, 73, 77, 77, 71, 68, 65, 77, 67, 66.

What is the range?

516.20

144.00

12.00

22.72

4.77

A quantity that measures the variation of a population or a sample relative to its mean is called the ____________.

coefficient of variation

range

variance

interquartile range

standard deviation

The local amusement park was interested in the average wait time at their most popular roller coaster at the peak park time (2 p.m.). They selected 13 patrons and had them get in line between 2 and 3 p.m. Each was given a stopwatch to record the time they spent in line. The times recorded were as follows (in minutes): 118, 124, 108, 116, 99, 120, 148, 118, 119, 121, 45, 130, 118.

What is the mean?

114.15

118

115.5

45

148

The median is the measure of central tendency that divides a population or sample into four equal parts.

True

False

Personnel managers usually want to know where a job applicant ranked in his or her graduating class. With a grade point average of 3.83, Michelle Robinson graduated above the 93rd percentile of her graduating class. What is the percentile rank of a student whose GPA was the median GPA.

10th

50th

93rd

25th

75th

The local amusement park was interested in the average wait time at their most popular roller coaster at the peak park time (2 p.m.). They selected 13 patrons and had them get in line between 2 and 3 p.m. Each was given a stopwatch to record the time they spent in line. The times recorded were as follows (in minutes).

118, 124, 108, 116, 99, 120, 148, 118, 119, 121, 45, 130, 118

What is the IQR?

30

5

7

28

103

A plant manager knows that the number of boxes of supplies received weekly is normally distributed with a mean of 200 and a standard deviation of 20. What percentage of the time will fewer than 160 boxes of supplies arrive in a week?

2.28%

4.56%

42.07%

57.93%

The z value tells us the number of standard deviations that a value x is from the mean.

True

False

An event is a collection of sample space outcomes.

True

False

Determine whether these two events are mutually exclusive: consumer with an unlisted phone number and a consumer who does not drive.

not mutually exclusive

mutually exclusive

Determine whether these two events are mutually exclusive: unmarried person and a person with an employed spouse.

not mutually exclusive

mutually exclusive

Which of the following statements about the binomial distribution is not correct?

Each trial results in a success or failure.

Trials are independent of each other.

The experiment consists of n identical trials.

The random variable of interest is continuous.

The probability of success remains constant from trial to trial.

For a continuous random variable x, the height of the probability curve f(x) at a particular point indicates the value of the probability for that value.

True

False

An important part of the customer service responsibilities of a cable company is the speed with which trouble in service can be repaired. Historically, the data show that the likelihood is 0.75 that troubles in a residential service can be repaired on the same day. For the first five troubles reported on a given day, what is the probability that all five will be repaired on the same day?

.2373

.9990

.0010

.6328

A standard normal distribution has a mean of ____________ and standard deviation of ____________.

zero, one

zero, zero

one, zero

one, one

A letter is drawn from the alphabet of 26 letters. What is the probability that the letter drawn is a vowel?

5/26

21/26

1/26

4/26

The set of all possible outcomes for an experiment is called a(n) ____________.

event

probability

sample space

experiment

Using the following probability distribution table of the random variable x, what is the probability of x = 3?

5/15

2/15

1/15

3/15