Introduction to the Practice of Statistics 9th edition by David S. Moore Test bank

 C)360 days
 D)760 days
 
 
129.The Michigan Department of Transportation (M-DOT) is working on a major project: 80% of the highways in Michigan need to be repaved. To speed completion of this project, many contractors will be working for M-DOT. Contractors are currently bidding on the next part of the project. To help make a decision about which contractor to hire, M-DOT collects many variables besides just the estimated cost. One of those variables is the contractor's estimate of the number of workdays required to finish the job. Twenty contractors have bid on the next job. The boxplot below represents their estimates of the number of work days required.

 
Determine whether each of the following statements is true or false.
A)The median number of days is approximately 180.
B)The minimum number of days is approximately 40.
C)The maximum number of days is approximately 750.
D)Twenty-five percent of contractors estimated the number of days to be more than 100.
 
 
130.The asking prices (in thousands of dollars) for a sample of 13 houses currently on the market in Neighborville are listed below. For convenience, the data have been ordered.
 
175199205234259275299304317345355384549
 
What is the five-number summary?
 A)175     234     299     331     549
 B)199     219.5     299     350     549
 C)175     219.5     299     350     384
 D)None  of the above
 
 
131.The asking prices (in thousands of dollars) for a sample of 13 houses currently on the market in Neighborville are listed below. For convenience, the data have been ordered.
 
175199205234259275299304317345355384549
 
Use the 1.5 × IQR rule to determine if there are any outliers present. What is/are the value(s) of the outlier(s)?
 A)There are no outliers present.
 B)One outlier: 175
 C)One outlier: 549
 D)Two outliers: 175 and 549
 
 
132.The following boxplot is of the birth weights (in ounces) of 160 infants born in a local hospital.
 

The median birth weight is approximately ________________.
 A)90 ounces
 B)100 ounces
 C)110 ounces
 D)120 ounces
 
 
133.The following boxplot is of the birth weights (in ounces) of 160 infants born in a local hospital.
 

 
About 40 of the birth weights were below _______________.
 A)92 ounces
 B)102 ounces
 C)112 ounces
 D)122 ounces
 
 
134.The following boxplot is of the birth weights (in ounces) of 160 infants born in a local hospital.
 

 
Approximately __________ children had birth weights between 102 and 122 ounces.
 A)40
 B)50
 C)80
 D)100
 
 
135.This is a standard deviation contest. Which of the following sets of four numbers has the largest possible standard deviation?
 A)7, 8, 9, 10
 B)5, 5, 5, 5
 C)0, 0, 10, 10
 D)0, 1, 2, 3
 
 
136.A sample of 16 people is taken, and their weights are measured. The standard deviation of these 16 measurements is computed to be 5.4.What is the variance of these measurements?
 A)2.24 pounds
 B)2.24 pounds2
 C)29.16 pounds
 D)29.16 pounds2
 
 
137.There are three children aged three, four, and five in a room. If another four-year-old child enters the room, what will happen to the mean and variance?
 A)The mean will stay the same, but the variance will increase.
 B)The mean will stay the same, but the variance will decrease.
 C)The mean and variance will both stay the same.
 D)The mean and variance will both decrease.
 
 
138.The standard deviation s is a useful measure of a characteristic of a distribution of data values. Which of the following statements about s is FALSE?
 A)The standard deviation measures the spread of the data around the mean.
 B)The standard deviation is appropriate as a measure of spread when the mean is chosen as the measure of center.
 C)The standard deviation can never be zero.
 D)The standard deviation is not resistant; a few outliers can make s very large.
 E)As the data values become more spread out about their mean, s becomes larger.
 
 
139.The salaries paid to the eight employees of a small market research company are as follows: the five telephone interviewers are each paid $32,000; two administrative assistants are paid $48,000; a supervisor is paid $60,000; and the senior manager is paid $190,000. The number of employees earning more than the mean salary is