MATH 3339 FINAL EXAM
QUESTIONS AND ANSWERS 100%
CORRECT
Suppose that in a large metropolitan area, 73% of all households have cable tv.
Suppose you are interested in selecting a group of six households from this area. Let
X be the number of households in a group of six households from this area that have
cable tv. For what proportion of groups will at most two of the households have cable
tv? - ANSWER-pbinom (2,6,.73)
A potato chip company calculated that there is a mean of 75.4 broken potato chips in
each production run with a standard deviation of 5.2. If the distribution is
approximately normal, find the probability that there will be fewer than 66 broken
chips in a run. - ANSWER-pnorm(66,75.4,5.2)
A distribution of grades in an introductory statistics class (where A = 4, B = 3, etc) is:
x= 0,1,2,3,4
p(x)= 0.1,0.18,.22,.31,.19
find the mean and variance - ANSWER-sum(x*p)
sum(x^2*p)-(sum(x*p)^2)
The weights of male and female students in a class are summarized in the following
boxplots:
Which of the following is NOT correct? - ANSWER-The male students have less
variability than the female students.
The following table displays the results of a sample of 100 in which the subjects
indicated their favorite ice cream of three listed. The data are organized by favorite
ice cream and age group. What is the probability that a person chosen at random will
be between 20 and 40 years old if he or she favors vanilla?
Vanilla (20,40) = 9
All Vanilla = 9 + 9 + 16 - ANSWER-9 / (9+9+16) = 9/34
A random sample of 144 observations produced a sample proportion of 0.35. An
approximate 90% confidence interval for the population proportion p is between -
ANSWER-0.35+c(-1,1)*qnorm(1.9/2)*sqrt(0.35*(1-0.35)/144)
Data for gas mileage (in mpg) for different vehicles was entered into a software
package and part of the ANOVA table is shown below:
P(A) = 0.31, P(B)=0.46 and P(AnB)=0.14, find P(AIB) - ANSWER-0.,14/0.46
Source DF SS MS
Vehicle 5 505 252.50
Error 6 202 33.67
QUESTIONS AND ANSWERS 100%
CORRECT
Suppose that in a large metropolitan area, 73% of all households have cable tv.
Suppose you are interested in selecting a group of six households from this area. Let
X be the number of households in a group of six households from this area that have
cable tv. For what proportion of groups will at most two of the households have cable
tv? - ANSWER-pbinom (2,6,.73)
A potato chip company calculated that there is a mean of 75.4 broken potato chips in
each production run with a standard deviation of 5.2. If the distribution is
approximately normal, find the probability that there will be fewer than 66 broken
chips in a run. - ANSWER-pnorm(66,75.4,5.2)
A distribution of grades in an introductory statistics class (where A = 4, B = 3, etc) is:
x= 0,1,2,3,4
p(x)= 0.1,0.18,.22,.31,.19
find the mean and variance - ANSWER-sum(x*p)
sum(x^2*p)-(sum(x*p)^2)
The weights of male and female students in a class are summarized in the following
boxplots:
Which of the following is NOT correct? - ANSWER-The male students have less
variability than the female students.
The following table displays the results of a sample of 100 in which the subjects
indicated their favorite ice cream of three listed. The data are organized by favorite
ice cream and age group. What is the probability that a person chosen at random will
be between 20 and 40 years old if he or she favors vanilla?
Vanilla (20,40) = 9
All Vanilla = 9 + 9 + 16 - ANSWER-9 / (9+9+16) = 9/34
A random sample of 144 observations produced a sample proportion of 0.35. An
approximate 90% confidence interval for the population proportion p is between -
ANSWER-0.35+c(-1,1)*qnorm(1.9/2)*sqrt(0.35*(1-0.35)/144)
Data for gas mileage (in mpg) for different vehicles was entered into a software
package and part of the ANOVA table is shown below:
P(A) = 0.31, P(B)=0.46 and P(AnB)=0.14, find P(AIB) - ANSWER-0.,14/0.46
Source DF SS MS
Vehicle 5 505 252.50
Error 6 202 33.67
