MATH 3339 FINAL EXAM | QUESTIONS AND ANSWERS | SPRING 2026 - UNIVERSITY OF
HOUSTON.
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.
P(A) = 0.31, P(B)=0.46 and P(AnB)=0.14, find P(AIB) - (answer)0.,14/0.46
Identify the most appropriate test to use for the following situation:A private and a public university are
located in the same city. For the private university, 1046 alumni were surveyed and 653 said that they
attended at least one class reunion. For the public university, 791 out of 1327 sampled alumni claimed
they have attended at least one class reunion. Is the difference in the sample proportions statistically
significant? - (answer)Two sample z test for proportions
A random sample of 121 cans of fruit nectar is drawn from among all cans produced in a run. Prior
experience has shown that the distribution of the contents has a mean of 12.13 ounces and a standard
deviation of 2.14 ounce. What is the probability that the average contents of the 121 sample cans is less
than 11.81 ounces? - (answer)pnorm(11.81,12.13,2.14/sqrt(121))
HOUSTON.
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.
P(A) = 0.31, P(B)=0.46 and P(AnB)=0.14, find P(AIB) - (answer)0.,14/0.46
Identify the most appropriate test to use for the following situation:A private and a public university are
located in the same city. For the private university, 1046 alumni were surveyed and 653 said that they
attended at least one class reunion. For the public university, 791 out of 1327 sampled alumni claimed
they have attended at least one class reunion. Is the difference in the sample proportions statistically
significant? - (answer)Two sample z test for proportions
A random sample of 121 cans of fruit nectar is drawn from among all cans produced in a run. Prior
experience has shown that the distribution of the contents has a mean of 12.13 ounces and a standard
deviation of 2.14 ounce. What is the probability that the average contents of the 121 sample cans is less
than 11.81 ounces? - (answer)pnorm(11.81,12.13,2.14/sqrt(121))
