Assignment: 1-3 MyStatLab: Module | Complete Solution

Course: MAT-240

Assignment: 1-3 MyStatLab: Module
One Problem Set

1: Planned Electronic Device Replacement
The following data represent the percent of owners of an electronic device that plan to purchase a replacement device
within the next 12 months based on a survey of 1100 adults in a certain country. Complete parts (a) through (c).
Click the icon to view the bar chart of the data. 1
(a) What percent of game console owners plan to buy a replacement device within the next 12 months?
%
(b) If there are 250 million individuals who own a cell phone, how many expect to replace their phone within the next
12 months?
(c) If the results of the survey were claimed to indicate that % of adults in this country who own digital cameras plan to
replace their camera in the next 12 months, would you say this statement is descriptive or inferential? Why?
7.9
A. The statement is inferential, because the survey reports on a sample of the country's population. This
claim requires an inference to the population.
B. The statement is inferential, because the survey results are unlikely to be similar to the results for
the country's population.
C. The statement is descriptive, because the claim is stating what has been determined by the survey.
D. The statement is descriptive, because the survey sampled enough adults in the country to be certain
that its results apply to the population.
0 5 10 15 20 25
DVD Player
TV
Game Console
Digital Camera
Cell Phone
PC
Percent
6.4%
12.2%
10.5%
7.9%
14.7%
18.9%
Owners Planning to Replace
Electronic Device
2. A library took a survey to find the age distribution of 50
randomly selected new youth members. The results are
shown in the table below.
Age Group Number of New Members
3-5
6-8
9-11
12-14
15-17
4
7
11
22
6
(a) Construct a relative frequency distribution of the data.
Age Group Relative Frequency
3-5
6-8
9-11
12-14
15-17
(b) What percentage of new youth members are in the
6-8 age group?
%
(c) What percentage of the new youth members are age
8 or younger?
%
3. The data to the right represent the number of people from a
certain county, aged 5 to 64, who visited an optometrist over
the course of last year.
Age Patients
5-19
20-34
35-49
50-64
1781
4647
5807
6004
(a) Create a relative frequency distribution. (Round to three decimal places as needed.)
Age Relative Frequency
5-19
20-34
35-49
50-64
(b) Create a frequency histogram. Choose the correct answer below.
A.
0
2000
4000
6000
8000
Age
Frequency
B.
0
2000
4000
6000
8000
Age
Frequency
C.
0
2000
4000
6000
8000
Age
Frequency
D.
0
2000
4000
6000
8000
Age
Frequency
(c) Create a relative frequency histogram. Choose the correct answer below.
A.
0
0.1
0.2
0.3
0.4
0.5
Age
Relative Frequency
B.
0
0.1
0.2
0.3
0.4
0.5
Age
Relative Frequency
C.
0
0.1
0.2
0.3
0.4
0.5
Age
Relative Frequency
D.
0
0.1
0.2
0.3
0.4
0.5
Age
Relative Frequency
(d) What percentage of patients were between 35 and 49?
%
(Round to the nearest tenth as needed.)
(e) What percentage of patients were 34 or younger?
%
(Round to the nearest tenth as needed.)
5-19
20-34
35-49
50-64
5-19
20-34
35-49
50-64
5-19
20-34
35-49
50-64
5-19
20-34
35-49
50-64
5-19
20-34
35-49
50-64
5-19
20-34
35-49
50-64
5-19
20-34
35-49
50-64
5-19
20-34
35-49
50-64
4.
5.
2: College Enrollment
The accompanying data represent the percentage of recent high school graduates (graduated within 12 months before the
given year-end) who enrolled in college in the fall. Construct a time-series plot and comment on any trends.
Click the icon to view the data table. 2
Choose the correct time-series plot below.
A.
1989 1997 2005
58
64
70
Year
Percent Enrolled
B.
1989 1997 2005
58
64
70
Year
Percent Enrolled
C.
1989 1997 2005
58
64
70
Year
Percent Enrolled
Comment on any trends. Choose the correct comment below.
A. There are not any trends.
B. The percentage of high school graduates who enrolled in college has generally increased, though there
have been some down years.
C. The percentage of high school graduates who enrolled in college has generally decreased, though
there have been some up years.
Full data
set
Year Percent Enrolled Year Percent Enrolled
1989 59.4 1998 65.6
1990 60.1 1999 62.9
1991 62.3 2000 63.3
1992 61.7 2001 61.5
1993 62.5 2002 65.2
1994 61.7 2003 63.9
1995 61.7 2004 66.7
1996 65.0 2005 68.6
1997 67.0
For a large sporting event the broadcasters sold ad slots for a total revenue of $ million. What was the mean price
per ad slot?
63 140
The mean price per ad slot was $ million.
(Round to one decimal place as needed.)
College Enrollment College Enrollment College Enrollment
6.
7.
The following data represent the monthly cell phone bill for a person's phone for six randomly selected months.
$35.28, $42.09, $39.45, $38.93, $43.39, $49.26
Compute the mean, median, and mode phone bill.
The mean phone bill is $ . (Round to the nearest cent as needed.)
The median phone bill is $ . (Round to the nearest cent as needed.)
Compute the mode phone bill. Choose the correct answer below.
A. The mode phone bill is $43.39.
B. The mode phone bill is $35.28.
C. The mode phone bill is $39.45.
D. There is no mode phone bill.
A random sample of 15 college students were asked "How many hours per week typically do you
work outside the home?" Their responses are shown on the right.
Determine the shape of the distribution of hours worked by drawing a frequency histogram and
computing the mean and median. Which measure of central tendency better describes
hours worked?
6 31 0
7 8 14
18 10 17
19 13 27
12 6 14
Choose the correct frequency histogram below.
A.
0 10 20 30
0
2
4
hours
Frequency
B.
0 10 20 30
0
2
4
hours
Frequency
C.
0 10 20 30
0
2
4
hours
Frequency
Is the histogram for the data set skewed right, skewed left, or symmetric?
skewed right
symmetric
skewed left
The mean number of hours worked by college students outside the home is approximately hours.
(Type an integer or decimal rounded to three decimal places as needed.)
The median number of hours worked by college students outside the home is hours.
Which measure of central tendency better describes hours worked?
mean
median
mode
Hours Worked
per Week
Hours Worked
per Week
Hours Worked
per Week
8.
9.
10.
Compute the range and sample standard deviation for strength of the concrete (in psi).
3910, 4060, 3100, 3000, 2910, 3870, 4060, 4020
The range is psi.
s = psi (Round to one decimal place as needed.)
The following data represent the flight time (in minutes) of a random sample of seven flights from one city to another city.
287, 270, 260, 266, 257, 264, 258
Compute the range and sample standard deviation of flight time.
The range of flight time is minutes.
The sample standard deviation of flight time is minutes.
(Type an integer or decimal rounded to one decimal place as needed.)
The following data for a random sample of banks in two cities represent the ATM fees for using another bank's ATM.
Compute the range and sample standard deviation for ATM fees for each city. Which city has the most dispersion based
on range? Which city has more dispersion based on the standard deviation?
City A 2.50 1.25 1.25 0.00 1.75
City B 1.00 1.00 1.50 1.50 1.25
The range for city A is $ .
The range for city B is $ .
The standard deviation for city A is $ .
(Round to the nearest cent as needed.)
The standard deviation for city B is $ .
(Round to the nearest cent as needed.)
Which city has the most dispersion based on range?
A. City A, because it has a lower range.
B. City A, because it has a higher range.
C. City B, because it has a higher range.
D. City B, because it has a lower range.
Which city has the most dispersion based on standard deviation?
A. City A, because it has a lower standard deviation.
B. City B, because it has a higher standard deviation.
C. City B, because it has a lower standard deviation.
D. City A, because it has a higher standard deviation.
11.
12.
13.
Determine whether the random variable is discrete or continuous. In each case, state the possible values of the random
variable.
(a) The number of customers arriving at a bank between noon and 1:00 P.M..
(b) The time required to download a file from the Internet.
(a) Is the number of customers arriving at a bank between noon and 1:00 P.M. discrete or continuous?
A. The random variable is continuous. The possible values are x ≥ 0.
B. The random variable is discrete. The possible values are x ≥ 0.
C. The random variable is discrete. The possible values are x = 0, 1, 2,....
D. The random variable is continuous. The possible values are x = 0, 1, 2,....
(b) Is the time required to download a file from the Internet discrete or continuous?
A. The random variable is continuous. The possible values are t > 0.
B. The random variable is continuous. The possible values are t = 1, 2, 3, ....
C. The random variable is discrete. The possible values are t = 1, 2, 3, ....
D. The random variable is discrete. The possible values are t > 0.
Determine the required value of the missing probability to make
the distribution a discrete probability distribution.
x P(x)
3 0.18
4 ?
5 0.46
6 0.11
P(4) = (Type an integer or a decimal.)
The probability histogram to the right
represents the number of live births by
a mother to years old who had a
live birth in .
44 49
2012
1 2 3 4 5 6 7 8
0.00
0.05
0.10
0.15
0.20
0.25
0.30
Child
Probability
(a) What is the probability that a randomly selected - to -year-old mother who had a live birth in has had her
fourth live birth?
44 49 2012
(Type an integer or a decimal.)
(b) What is the probability that a randomly selected - to -year-old mother who had a live birth in has had her
fourth or fifth live birth?
44 49 2012
(Type an integer or a decimal.)
(c) What is the probability that a randomly selected - to -year-old mother who had a live birth in has had her
sixth or more live birth?
44 49 2012
(Type an integer or a decimal.)
(d) If a - to -year-old mother who had a live birth in is randomly selected, how many live births would you expect
the mother to have had?
44 49 2012
(Round to one decimal place as needed.)
0.239
0.256
0.167
0.109
0.097
0.034 0.041
0.057
14. Suppose a life insurance company sells a $ one-year term life insurance policy to a -year-old female for
$ . The probability that the female survives the year is . Compute and interpret the expected value of this
policy to the insurance company.
240,000 22
250 0.999582
The expected value is $ .
(Round to two decimal places as needed.)
Which of the following interpretation of the expected value is correct?
A. The insurance company expects to make an average profit of $ on every female it
insures for 1 month.
22.72 22-year-old
B. The insurance company expects to make an average profit of $ on every female it
insures for 1 year.
149.68 22-year-old
C. The insurance company expects to make an average profit of $ on every female it
insures for 1 year.
249.90 22-year-old
D. The insurance company expects to make an average profit of $ on every female it
insures for 1 month.
13.61 22-year-old