question

After constructing a relative frequency distribution summarizing IQ scores of college students, what should be the sum of the relative frequencies?

answer

If percentages are used, the sum should be 100%. If proportions are used, the sum should be 1.

question

Among fatal plane crashes that occurred during the past 70 years, 269 were due to pilot error, 54 were due to other human error, 665 were due to weather, 85 were due to mechanical problems, and 479 were due to sabotage.
Construct the relative frequency distribution. What is the most serious threat to aviation safety, and can anything be done about it?
What is the relative frequency for pilot error, other human error, weather, mechanical problems, and sabotage? Round to one decimal point.
What is the most serious threat to aviation safety, and can anything be done about it?

answer

Pilot Error: 17.3%
Other Human Error: 3.5%
Weather: 42.8%
Mechanical problems: 5.5%
Sabotage: 30.9%
Weather is the most serious threat to aviation safety. Weather monitoring systems could be improved. Whi

question

Which characteristic of data is a measure of the amount that the data values vary?
a. variation
b. distribution
c. time
d. center

answer

variation

question

- are sample values that lie very far away from the majority of the other sample values.

answer

outliers

question

A -- helps us understand the nature of the distribution of a data set.

answer

frequency distribution

question

Class width is found by -------.

answer

subtracting a lower class limit from the next consecutive lower class limit

question

In a -- distribution, the frequency of a class is replaced with a proportion or percent.

answer

relative frequency

question

The population of ages at inauguration of all U.S. Presidents who had professions in the military is 62, 46, 68, 64, 57. Why does it not make sense to construct a histogram for this data set?

answer

With a data set that is so small, the true nature of the distribution cannot be seen with a histogram.

question

Listed below are blood groups of O, A, B, and AB of randomly selected blood donors. Construct the relative frequency distribution.
A O O O O A A O A O
O A A O O AB O A B A
AB O A O B O O AB A A
AB A O A B O AB O O O
Find the relative frequency for O, A, B, AB

answer

O: 47.5%
A: 32.5%
B: 7.5%
AB:12.5%

question

Use the given qualitative data to construct the relative frequency distribution.
The 2445 people aboard a ship that sank include 325 male survivors, 1661 males who died, 322 female survivors, and 137 who died.
Find the relative frequency for male survivors, males who died, female survivors, and females who died.

answer

Male Survivors: 13.3%
Males who died: 67.9%
Female survivors: 13.2%
Females who died: 5.6%

question

The data represents the body mass index (BMI) values for 20 females. Construct a frequency distribution beginning with a lower class limit of 15.0 and use a class width of 6.0. Does the frequency distribution appear to be roughly a normal distribution?
17.7 33.5 26.9 22.5 24.9
28.9 22.8 18.3 27.8 22.6
19.2 22.4 21.2 37.7 40.4
27.7 44.9 30.3 29.1 21.7
Find the frequency for body mass indexes between:
15.0-20.9
21.0-26.9
27.0-32.9
33.0-38.9
39.0-44.9
Does the frequency distribution appear to be roughly a normal distribution?

answer

15.0-20.9 ---------- 3
21.0--26.9 ---------- 8
27.0-32.9 -------------- 5
33.0-38.9 ---------- 2
39.0-44.9 -----------2
No, although the frequencies start low, increase to some maximum, then decrease, the distribution is not symmetric.

question

The data represents the daily rainfall (in inches) for one month. Construct a frequency distribution beginning with a lower class limit of 0.00 and use a class width of 0.20. Does the frequency distribution appear to be roughly a normal distribution?
0.39 0 0 0.28 0 0.56
0 0.18 0 0 1.36 0
0.16 0 0.01 0 0.16 0
0.11 0.42 0 0.01 0 0.27
0 0.11 0 0 0.15 0
Find the frequencies for daily rainfall in ranges:
0.00-0.19
0.20-0.39
0.40-0.59
0.60-0.79
0.80-0.99
1.00-1.19
1.20-1.39
Does the frequency distribution appear to be roughly a normal distribution?

answer

0.00-0.19----------- 24
0.20-0.39------------ 3
0.40-0.59------------ 2
0.60-0.79------------ 0
0.80-0.99------------ 0
1.00-1.19------------ 0
1.20-1.39----------- 1
No, the distribution is not symmetric, the frequencies do not start off low.

question

Look at #11 at the charts and answer the question:
Does the result appear to have a normal distribution? Why or why not?

answer

Yes, because the frequencies start low, reach a maximum, then become low again, and are roughly symmetric about the maximum frequency.

question

Look at #10 charts and answer the two questions:
Based on the distribution, do the weights appear to be reported or actually measured?
What can be said about the accuracy of the results?

answer

The weights appear to be reported because there are disproportionately more 0s and 5s.
They are likely not very accurate because they appear to be reported.

question

Look at #7 charts and answer the question:
Do cigarette filters appear to be effective?

answer

Yes, because the relative frequency of the higher tar classes is greater for nonfiltered cigarettes.

question

Look at #6 chart and answer the question:
Does the frequency distribution appear to have a normal distribution? Explain.

answer

Yes, because the frequencies start low, proceed to one or two high frequencies, then decrease to a low frequency, and the distribution is approximately symmetric.

question

Look at #5 chart and answer the question:
Does the frequency distribution appear to have a normal distribution?

answer

No, the distribution does not appear to be normal.

question

Look at #4 chart and answer the questions:
What is the class width?
What are the class midpoints?
What are the class boundaries?

answer

3
6.45, 9.45, 12.45, 15.45, 18.45
4.95, 7.95, 10.95, 13.95, 16.95, 19.95

question

Look at #3 chart and answer the questions:
What is the class width?
What are the class midpoints?
What are the class boundaries?

answer

3
65.45, 68.45, 71.45, 74.45, 77.45, 80.45, 83.45, 86.45, 89.45, 92.45
63.95, 66.95, 69.95, 72.95, 75.95, 78.95, 81.95, 84.95, 87.95, 90.95, 93.95

question

Look at #2 chart and answer the questions:
What is the class width?
What are the class midpoints?
What are the class boundaries?

answer

3
51, 54, 57, 60, 63, 66, 69
49.5, 52.5, 55.5, 58.5, 61.5, 64.5, 67.5, 70.5

question

Look at #23 chart and answer the question:
The histogram represents - debate team members.

answer

11

question

Look at #24 chart and answer the questions:
What is the class width?
What are the approximate lower and upper class limits of the first class?

answer

20
Lower class: 105
Upper class: 125

question

Look at #25 chart and answer the questions:
Construct a histogram on the calculator.
Are the data reported or measured?

answer

The data appears to be measured. The heights occur with roughly the same frequency.

question

Look at #26 chart and answer the questions:
Construct a histogram on the calculator.
Do the data appear to have a distribution that is approximately normal?

answer

Yes. It is approximately normal.

question

Look at #27 chart and answer the questions:
Construct a histogram on the calculator.
Does the histogram appear to depict data that have a normal distribution?

answer

The histogram appears to depict a normal distribution. The frequencies generally increase to a maximum and then decrease, and the histogram is roughly symmetric.

question

Look at #28 chart and answer the questions:
Construct a histogram on the calculator.
Does the histogram appear to depict data that have a normal distribution?

answer

The histogram appears to roughly approximate a normal distribution. The frequencies generally increase to a maximum and then decrease, and the histogram is symmetric.

question

Look at #29 chart and answer the questions:
Construct a histogram on the calculator.
Do the data appear to have a distribution that is approximately normal?

answer

No, it is not symmetric

question

Look at #30 charts and answer the questions:
Construct a histogram on the calculator.
Does the histogram appear to depict data that have a normal distribution?

answer

The histogram appears to roughly approximate a normal distribution. The frequencies generally increase to a maximum and then decrease and the histogram is symmetric.

question

Look at #31 chart and answer the questions:
Construct a histogram on the calculator.
Which part of the histogram depicts flights that arrived early, and which part depicts flights that arrived late?

answer

The two leftmost bars depict flights that have arrived early, and the other bars to the right depict flights that arrived late.

question

The heights of the bars of a histogram correspond to - values.

answer

frequency

question

The bars in a histogram -.

answer

touch

question

A histogram aids in analyzing the - of the data.

answer

shape of the distribution

question

A -- histogram has the same shape and horizontal scale as a histogram but the vertical scale is marked with relative frequencies instead of actual frequencies.

answer

relative frequency

question

A(n) - distribution has a "bell" shape.

answer

normal

question

A bar chart and a Pareto chart both use bars to show frequencies of categories of categorical data. What characteristic distinguishes a Pareto chart from a bar chart, and how does that characteristic help us in understanding the data?

answer

In a Pareto chart, the bars are always arranged in descending order according to frequencies. The Pareto chart helps us understand data by drawing attention to the more important categories, which have the highest frequencies.

question

Look at #38 chart and question and answer the questions:
Construct a scatterplot on the calculator.
Does there appear to be a correlation between the president's height and his opponent's height?

answer

No, there does not appear to be a correlation because there is no general pattern to the data.

question

Look at #39 chart and answer the questions?
Construct a scatterplot on the calculator.
Is there a relationship between cigarette tar and CO?

answer

Yes, as the amount of tar increases the amount of carbon monoxide also increases.

question

Look at #40 and answer the questions:
Construct a time-series graph (line graph) on the calculator.
What is the trend? How does this trend compare to the trend for drive-in movie theaters?

answer

There appears to be an upward trend, unlike drive-in movie theatres, which have a downward trend.

question

Look at the #41 charts and answer the questions:
Does the configuration of the points appear to suggest that the volumes are from a population with a normal distribution?
Are there any outliers?

answer

Yes, the population appears to have a normal distribution because the dotplot resembles a "bell" shape.
Yes, the volume of 50 oz appears to be an outlier because it is far away from the other volumes.

question

Look at the #42 charts and answer the questions:
Is there strong evidence suggesting that the data are not from a population having a normal distribution?

answer

No, the distribution is not dramatically far from being a normal distribution with a "bell" shape, so there is not strong evidence against a normal distribution.

question

Look at the #43 charts and answer the question:
Which graph is more effective in showing the relative importance of the causes of work-related deaths?

answer

The Pareto chart is better because it more clearly draws attention to the main cause of work-related death.

question

Look at the #44 charts and answer the questions:
If someone would like to get a job, what seems to be the most effective approach?

answer

Help-wanted ads (H)

question

Look at the #45 charts and answer the questions:
Compare the pie chart found above to the Pareto chart given on the left. Can you determine which graph is more effective in showing the relative importance of job sources?

answer

The Pareto char is more effective.

question

Look at the #46 charts and answer the questions:
Applying a loose interpretation of the requirements for a normal distribution, does the data appear to be normally distributed? Why or why not?

answer

The frequency polygon appears to roughly approximate a normal distribution because the frequencies increase to a maximum, then decrease, and the graph is roughly symmetric.

question

Look at #47 charts and answer the question:
Applying a strict interpretation of the requirements for a normal distribution, do the depths appear to be normally distributed? Why or why not?

answer

The frequency polygon does not appear to approximate a normal distribution because the frequencies do not increase to a maximum and then decrease, and the graph is not symmetric.

question

Look at #48 chart and answer the questions:
What impression does the graph create?
Does the graph depict the data fairly?

answer

The graph creates the impression that men have salaries that are more than twice the salaries of women.
No, because the vertical scale does not start at zero.

question

Look at #49 chart and answer the question:
Does the graph distort the data? Why or why not?

answer

Yes, because the graph incorrectly uses objects of volume to represent the data.

question

Look at #50 chart and answer the questions:
In what way might the graph be deceptive?
How much greater is the braking distance of Car A than the braking distance of Car C?

answer

By starting the horizontal axis at 100, the graph cut off portions of the bars.
The braking distance of Car A is about 30% greater than the braking distance of Car C.

question

Look at #51 chart and answer the questions:
Compare the results.

answer

The distribution of pulse rates for men is concentrated, centered around 60, whereas the distribution of pulse rates for women is more spread out, centered around 70.

question

A(n) -- uses line segments to connect points located directly above class midpoint values.

answer

frequency polygon

question

A - is a graph of each data value plotted as a point.

answer

dotplot

question

We utilize statistical - to look for the features that reveal some useful or interesting characteristics of the data set.

answer

graphs

question

A - is a plot of paired data (x,y) and is helpful in determining whether there is a relationship between the two variables.

answer

scatterplot

question

Which of the following is NOT true about statistical graphs?
a. They utilize areas or volumes for data that are one-dimensional in nature.
b. Similar graphs can be constructed in order to compare data sets.
c. They can be used to identify extreme data values.
d. They can be used to consider the overall shape of the distribution.

answer

a.

question

In a graph, if one or both axes begin at some value other than zero, the differences are exaggerated. This bad graphing method is known as ---.

answer

a nonzero axis

question

When drawings of objects are used to depict data, false impressions can be made. These drawings are called -.

answer

pictographs

question

Which of the following is a common distortion that occurs in graphs?
a. Using bars to represent the frequency of data values.
b. Using points above the class midpoints at the heights of the class frequencies.
c. Labeling both axes
d. Using a two-dimensional object to represent data that are one-dimensional in nature.

answer

d.

question

Why is it important to learn about bad graphs?

answer

So that we can critically analyze a graph to determine whether it is misleading.