Download Math 1181 Exam 1 Name: 1. Which of the following is a valid

Math 1181 Exam 1
1.
Name:
Which of the following is a valid variable if houses in your neighborhood are the
observational units in a study?
(a) the number of houses in your neighborhood
(b) the average number of windows for all houses
(c) whether or not the house is on a corner
(d) the proportion of houses that have a fence
2-3 A study was conducted to see if Smartfood Popcorn makes people smarter. A group of 50
participants in the study were divided into two groups. One group received Smartfood Popcorn
before taking a spelling test, and the other took the test without first getting popcorn.
2.
_______ is a categorical variable in the Smartfood study while _________ is a
quantitative variable. Which choice correctly fills in the blanks?
(a) the 50 participants; the test score for each participant
(b) the test score for each participant; the average score of the participants who received
Smartfood
(c) whether or not the participants received Smartfood; the test score for each participant
(d) the scores of those who received Smartfood; whether or not the participants received
Smartfood
3.
What are the observational units in the study?
(a) the 50 participants
(b) the popcorn
(c) the people conducting the study
(d) the people who grade the tests
4-6 The following histogram displays the total deaths by lightning strike over the ten year period
1997-2006 by state. Bins are of width 5 and range from 0-4, 5-9, 10-14, etc.
4.
This distribution is best described as…
(a) Symmetric with no outliers
(b) Skewed toward higher values with one outlier
(c) Skewed toward lower values with one outlier
(d) Skewed toward higher values with no outliers
5.
Because of the shape of the distribution we would expect the mean number of deaths to
be…
(a) less than the median
(b) about the same as the median
(c) greater than the median
(d) cannot be determined from the given information
6.
Which of the following is NOT true?
(a) 4 states had 20 or more deaths
(b) 20 states had fewer than 5 deaths
(c) exactly nine states had between 10 and 14 deaths
(d) a typical state had about 10 deaths
7.
Based on the dotplots of February temperatures for three cities, which of the following is
NOT true?
(a) San Luis Obispo experienced generally
higher temperatures than Sedona and Lincoln
(b) The distribution of temperatures for
Sedona is skewed toward lower values
(c) The city with the most consistent
temperatures was Sedona
(d) The temperatures in Lincoln tend to be
higher than those in Sedona
8-9 The following side-by-side boxplots represent the calories of different hotdogs grouped by
the type of meat.
8.
What percent of beef hotdogs have fewer than
140 calories?
(a) 15%
(b) 25%
(c) 50%
(d) 75%
9.
_____ tends to have fewer calories. _____ has
the widest range
(a) Poultry; Beef
(b) Poultry; Meat
(c) Beef; Poultry
(d) Beef; Meat
10.
Consider the following data set: {1, 7, 3, 3, 6, 4}
The mean and median for this data are:
(a.) 4 and 3
(b.) 4.8 and 3.5
(c.) 4 and 3.3
(d.) 4 and 3.5
11.
Which of the following is a measure of center which is not resistant? (Be careful, not all
the choices are measures of center.)
(a.) mean
(b.) standard deviation
(c.) IQR
(d.) median
12.
A distribution of 6 scores has a median of 21. If the highest score increases 3 points, the
median will become ___________.
(a.) 21
(b.) 21.5
(c.) 24
(d.) Cannot be determined without additional information.
Column
Husband's Age
Wife's Age
Median Min Max Q1 Q3
30.5
19
71 25 44.5
29
16
73 24 41.5
13.
Based on the 5-number summaries for the ages of a group of husbands and wives at
marriage, which of the following is NOT true?
(a.) the husbands tend to be older than the wives
(b.) every husband is older than his wife
(c.) the youngest person was a wife
(d.) the oldest person was a wife
14.
To say that 5th graders tend to be taller than 4th grader is to say that…
(a.) every child in 5th grade is taller than every child in 4th grade.
(b.) almost every child in 5th grade is taller than almost every child in 4th grade.
(c.) if you select a 4th grader and a 5th grader at random, more often than not, the 5th
grader will be taller
(d.) most 4th graders are not very tall.
15.
The dotplot to the right compares
some systolic and diastolic blood
pressure measurements. Which of the
following is NOT true?
(a.) systolic blood pressure tends to
be higher than diastolic blood pressure
(b.) systolic blood pressure reading
tend to be above 100
(c.) every systolic reading is higher
than every diastolic reading
(d.) diastolic blood pressure readings
tend to be below 100
16.
Two workers on the same job show the following results over a long period of time.
Worker A
Worker B
Mean time of completing the job (minutes) 30
25
Standard deviation (minutes)
6
4
Choose the best answer.
(a.) worker B tends to be faster but is less consistent than worker A
(b.) worker A tends to be faster and is more consistent
(c.) worker A tends to be faster but is less consistent than worker B
(d.) worker B tends to work faster and is more consistent
17.
Calculate the range and the IQR for the data set: {1, 3, 5, 6, 8, 10, 12}
(a.) 11 and 7
(b.) 12 and 6
(c.) 1 and 12
(d.) 6 and 3
18.
The measure of spread which is sensitive (not resistant) to extreme scores on the higher
or lower end of a distribution is the: (be careful, not every answer listed is a measure of
spread)
(a.) median.
(b.) mean.
(c.) standard deviation.
(d.) IQR
19.
According to the empirical rule (the 68-95-99.7 Rule), for any mound-shaped
distribution, about 95% of the data will be…
(a.) within one standard deviation of the mean
(b.) within two standard deviations of the mean
(c.) within three standard deviations of the mean
(d.) within four standard deviation of the mean
20.
If the mean of a distribution of test score is 80 and the standard deviation is 5, the
empirical rule predicts that about 68% of the students scored between…
(a.) 60 and 80
(b.) 70 and 80
(c.) 75 and 85
(d.) 65 and 95
21.
According to the empirical rule, if the distribution of the weights of a population of
candy bars is 1.4 ounces with a standard deviation of .05 ounces, what proportion of
candy bars would be expected to weigh between 1.05 ounces and 1.55 ounces
(a.) 68%
(b.) 84%
(c.) 95%
(d.) roughly all of them
22.
A distribution of 6 scores has an IQR of 24. If the highest score increases 3 points, the
new IQR will be:
(a.) 21
(b.) 21.5
(c.) 24
(d.) cannot be determined
23.
Adding 10 to each item in a set of data will result in which of the following:
(a.) increase the standard deviation by 10
(b.) multiply the IQR by 10
(c.) increase the mean by 10
(d.) increase the median by 2
24.
The following data is based on a survey of students' smoking habits taken in eight
Arizona high schools comparing smoking and nonsmoking teens based on whether both
parents, one parent or neither parent is a smoker:
smoker
non smoker
Total
both parents smoke
400
1380
1780
one smokes
416
1823
2239
neither smoke
188
1168
1356
1004
4371
5375
Total
Use the pie charts below to decide which of the following is NOT true about the
relationship between whether a teen smokes and whether both, one, or neither of their
parents smoke.
SMOKERS
NON-SMOKERS
(a.) Non-smokers are more likely to have parents who both do not smoke than smokers
(b.) Both smokers and non-smokers have about just as likely to have one parent who
smokes
(c.) Non-smokers parents are usually non-smokers
(d.) Smokers are more likely to have parents who both smoke than non-smokers are

25.
Compute the z-score for a score of 78 on a test with the following summary statistics:
min = 20, Q1 =70, med = 75, Q3 = 76, max = 100, s = 4, x = 70
(a) z = 2
(b) z = 2.5
(c) z = 0
(d) z = 7
26.
One hundred students took a test on which the mean score was 73 with a standard
deviation of 8. A grade of A was given to all who scored 85 or better. Approximately
how many A's were there, assuming scores were normally distributed? (Choose the
closest.)
(a.)
42
(b.)
7
(c.)
58
(d.)
5
27.
The stemplot below shows the number of hot dogs eaten by contestants in a recent hot
dog eating contest.
70|4 = 74 hotdogs
80|1
70|4 7
60|2 2 6
50|0 2 5 7 9
40|9
30|5 7 9
20|7 9
10|1
Which of the following statements are true?
I. The range is 70.
II. The median is 46.
III. The mean is 47.
(a)
(b)
(c)
(d)
(e)
28.
I only
II only
III only
I and II
I, II, and III
Consider this boxplot:
2
4
6
8
10
Which of the following statements are true?
I. The distribution is skewed right.
II. The interquartile range is about 8.
III. The median is about 10.
12
14
16
18
(a)
(b)
(c)
(d)
(e)
29.
I only
II only
III only
I and II
II and III
A national consumer magazine reported the following correlations.
The correlation between car weight and car reliability is -0.30.
The correlation between car weight and annual maintenance cost is 0.20.
Which of the following statements are true?
I. Heavier cars tend to be less reliable.
II. Heavier cars tend to cost more to maintain.
III. Car weight is related more strongly to reliability than to maintenance cost.
(a)
(b)
(c)
(d)
(e)
I only
II only
III only
I and II
I, II, and III
30.
Open the dataset “Governors05.” Construct a scatterplot of “Governor Salary” versus
“Median house value.” Which best describes the relationship?
(a.) positive, strong, linear, with no outliers
(b.) negative, moderate, linear, with an outlier
(c.) positive, moderate, linear with an outlier
(d.) no relationship
31.
In the scatterplot of “Governor Salary” versus “Median house value,” which state is an
outlier?
(a.)
Pennsylvania
(b.)
Hawaii
(c.)
California
(d.)
Alaska
32.
Calculate the correlation between “Median Housing Value” and “Governor Salary.”
(a) -.02
(b) .55
(c) .33
(d) -.55
33.
The stem-and-leaf display measures the salary of the employees at the XYZ
Manufacturing company.
The shape of the distribution is best described as
(3 | 5 means 35,000)
(a) Symmetric
(b) Skewed toward higher values
1|2
(c) Skewed toward lower values
2 | 0138
(d) Uniform
3 | 03638999
4 | 124556789
5 | 33356
6 | 078
7|2
34-35 Consider the histogram below of the
number of children in families at CSC.
34.
How many families are included in the
study ?
(a) 6
(b) 11
(c) 26
(d) 100
35.
The shape of the distribution is best described as
(a) Symmetric
(b) Skewed toward higher values
(c) Skewed toward lower values
(d) Uniform
36.
Refer to the dotplots of softball throwing distances for Machine Company and Tool
Company and choose the best answer without doing any calculations.
(a) Machine Company will have a greater mean and a greater standard deviation
(b) Machine Company will have a greater median and a smaller IQR
(c) Machine Company will have a smaller mean and a greater standard deviation
(d) Machine Company will have a greater median and a greater IQR
37-42 Use StatCrunch to access the data set “Broadway06.” The data show information on the
29 Broadway shows in production for the week of June 19-25, 2006.
37.
What are the observational units?
(a.)
Types
(b.)
Shows
(c.)
Gross receipts
(d.)
Top ticket price
38.
Which is a categorical variable?
(a.)
Types
(b.)
Shows
(c.)
Gross receipts
(d.)
Top ticket price
39.
Construct a Boxplot of Gross grouped by Type. Which is correct?
(a.)
Musicals tended to have higher gross receipts and more variability in gross
receipts than plays
(b.)
Plays tended to have higher gross receipts and more variability in gross receipts
than musicals
(c.)
Plays tended to have lower gross receipts and more variability in gross receipts
than musicals
(d.)
Musicals tended to have higher gross receipts and less variability in gross receipts
than plays
40.
Construct a scatterplot of %Capacity versus Top Ticket Price. Which of the following
best describes the relationship between these two variables?
(a.)
positive, strong, linear
(b.)
negative, strong, linear
(c.)
positive, moderate, nonlinear
(d.)
no relationship
41.
Construct a scatterplot of Gross Receipts versus Attendance. Which of the following best
describes the relationship between these two variables?
(a.)
positive, strong, linear
(b.)
negative, strong, linear
(c.)
positive, moderate, nonlinear
(d.)
no relationship
42.
Based on the scatterplot of Gross Receipts versus Attendance, if a new show opens next
week and has an attendance of 8000 people, what would be the most reasonable estimate
for the Gross Receipts of that show?
(a.)
$100,000
(b.)
$300,000
(c.)
$600,000
(d.)
$900,000
43.
Which is true?
(a) The closer a correlation coefficient is to 1, the more evidence there is of a causal
relationship between the explanatory variable and the response variable.
(b) The closer a correlation coefficient is to 0, the more evidence there is of a causal
relationship between the explanatory variable and the response variable.
(c) The closer the value of r is to -1, the more evidence there is of a causal relationship
between the explanatory variable and the response variable.
(d) It is never appropriate to draw conclusions about causality based on a correlation
alone.
44.
A negative z-score indicates…
(a) that someone made a computational error
(b) that the mean is a negative number
(c) that the distribution is skewed toward lower values
(d) that the item in question is below the mean
45.
The distribution of lifetimes for a certain type of light bulb is normally distributed with a
mean of 1000 hours and a standard deviation of 100 hours. Find the 33rd percentile of the
distribution of lifetimes.
(a.) 560
(b.) 330
(c.) 1044
(d.) 1440
(e.) none of these