QNT/275

STATISTICS FOR DECISION MAKING

The Latest Version A+ Study Guide

QNT 275T Apply Week 2 Connect® Exercise Week 2 Case Study

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

What is the standard deviation?

18

4.73

22.40

324

6.76

Which of the following graphical tools is not used to study the shapes of distributions?

stem-and-leaf display

scatter plot

histogram

dot plot

The following table shows the Price-to-Earnings ratio for a stereo equipment manufacturing company between 1998 and 2002.

Determine the percentage change in the P/E ratios from 1999 to 2000.

23.97%

31.53%

27.26%

−31.53%

−23.97%

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?

114.15

118

148

45

115.5

According to a survey of the top 10 employers in a major city in the Midwest, a worker spends an average of 413 minutes a day on the job. Suppose the standard deviation is 26.8 minutes and the time spent is approximately a normal distribution.

What are the times within which approximately 99.73 percent of all workers will fall?

[305.8, 520.2]

[386.2, 439.8]

[372.8, 453.2]

[359.4, 466.6]

[332.6, 493.4]

Using the following data, what would be the leaf unit in a stem-and-leaf display?

Picture

1.0

10

.10

.01

.20

A local electronics retailer recently conducted a study on purchasers of large screen televisions. The study recorded the type of television and the credit account balance of the customer at the time of purchase. They obtained the following results.

Picture

What percentage of purchases were plasma televisions by customers with the smallest credit balances?

50.00

39.20

56.30

34.80

19.60

______________ and _____________ are used to describe qualitative (categorical) data.

Stem-and-leaf displays, scatter plots

Scatter plots, histograms

Box plots, bar charts

Bar charts, pie charts

Pie charts, histograms

Suppose that a company’s annual sales were $1,200,000 in 1999. The annual growth rate of sales from 1999 to 2000 was 16 percent, from 2000 to 2001 it was −5 percent, and from 2001 to 2002 it was 22 percent.

The geometric mean growth rate of sales over this three-year period is calculated as 10.37 percent. Use the geometric mean growth rate and determine the forecasted sales for 2004.

1,780,678

1,200,014

1,965,337

1,613,371

1,422,197

9.

Award: 1 out of 1.00 point

A flaw possessed by a population or sample unit is ___________.

always random

a defect

displayed by a dot plot

the cause for extreme skewness to the right

10.

Award: 1 out of 1.00 point

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

bullet graph

sparkline

scatter plot

treemap

gauge

The Rivertown city council is attempting to choose one of four sites (A, B, C, or D) as the location for its new emergency facility. After the new emergency facility becomes available for service, the current emergency facility will be shut down. The project manager has estimated the following response times in minutes from each of the proposed sites to the four areas that must be served by the emergency facility.

Picture

The number of emergency runs from the current emergency facility to each of the four areas over the past year is as follows:

Picture

Compute the weighted mean response time from the proposed locations and determine which proposed site should be selected for the new emergency facility.

rev: 05_12_2017_QC_CS-89378

site A

site B

site C

site D

The average life of Canadian women is 73.75 years, and the standard deviation of the life expectancy of Canadian women is 6.5 years. Based on Chebyshev’s Theorem, determine the upper and lower bounds on the average life expectancy of Canadian women such that at least 90 percent of the population is included.

[12.09 135.41]

[8.75 138.75]

[53.20 94.30]

[66.38 81.13]

[67.25 80.25]

______________ and _____________ are used to describe qualitative (categorical) data.

Stem-and-leaf displays, scatter plots

Scatter plots, histograms

Box plots, bar charts

Bar charts, pie charts

Pie charts, histograms

A CFO is looking at what percentage of a company’s resources are spent on computing. He samples companies in the pharmaceutical industry and develops the following stem-and-leaf graph.

Picture

What would be the class length used in creating a frequency histogram?

1.4

8.3

1.2

1.7

0.9

All of the following are measures of central tendency except the ____________.

range

mode

mean

median

A CFO is looking at what percentage of a company’s resources are spent on computing. He samples companies in the pharmaceutical industry and develops the following stem-and-leaf graph.

Picture

What is the smallest percentage spent on R&D?

5.9

5.6

5.2

5.02

50.2

Recently an advertising company called 200 people and asked them to identify the company that was in an ad running nationwide. The following results were obtained.

Picture

What percentage of those surveyed could not correctly recall the company?

58.00

56.89

55.00

43.10

42.00

If a population distribution is skewed to the right, then, given a random sample from that population, one would expect that the ____________.

median would be greater than the mean

mode would be equal to the mean

median would be less than the mean

median would be equal to the mean

A relative frequency curve having a long tail to the right is said to be ___________.

skewed to the left

normal

a scatter plot

skewed to the right

According to Chebyshev’sTheorem, a range of how many standard deviations would include at least 80 percentof the values?

5.0

2.2

2.5

1.6

2.0

A histogram that tails out toward larger values is ___________.

skewed to the left

normal

a scatter plot

skewed to the right

When grouping a large sample of measurements into classes, the ______________ is a better tool than the ___________.

histogram, stem-and-leaf display

box plot, histogram

stem-and-leaf display, scatter plot

scatter plot, box plot

\