MATH 3339 - FINAL TEST | QUESTIONS AND ANSWERS | 2026 UPDATE | 100% CORRECT -
UNIVERSITY OF HOUSTON.
A potato chip company calculated that there is a mean of 75.2 broken potato chips in each production
run with a standard deviation of 5.4. If the distribution is approximately normal, find the probability that
there will be fewer than 67 broken chips in a run. - (answer)pnorm(67, mean = 75.2, sd = 5.4)
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
three of the households have cable tv? - (answer)pbinom(3, size = 6, prob = .73)
Find a value of c so that P(Z <= c) = .76 - (answer)qnorm(.76)
If the P-value is larger than the level of significance α, then the researcher should __________ at level α
- (answer)Fail to reject the null hypothesis
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).35 + c(-1, 1) * qnorm(1-.10/2)
* sqrt((.35* (1-.4))/144)
One-proportion z-test
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
The one-sample t statistic for a test of H0: μ = 13 vs. Ha: μ < 13 based on n = 17 observations has the test
statistic value of t = −1.45. What is the p-value for this test? - (answer)pt(-1.45, 16)
A random sample of 169 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 12.11 ounces and a standard
deviation of 2.11 ounce. What is the probability that the average contents of the 169 sample cans is less
than 11.86 ounces? - (answer)pnorm(11.86, mean = 12.11, sd = 2.11/sqrt(169))
UNIVERSITY OF HOUSTON.
A potato chip company calculated that there is a mean of 75.2 broken potato chips in each production
run with a standard deviation of 5.4. If the distribution is approximately normal, find the probability that
there will be fewer than 67 broken chips in a run. - (answer)pnorm(67, mean = 75.2, sd = 5.4)
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
three of the households have cable tv? - (answer)pbinom(3, size = 6, prob = .73)
Find a value of c so that P(Z <= c) = .76 - (answer)qnorm(.76)
If the P-value is larger than the level of significance α, then the researcher should __________ at level α
- (answer)Fail to reject the null hypothesis
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).35 + c(-1, 1) * qnorm(1-.10/2)
* sqrt((.35* (1-.4))/144)
One-proportion z-test
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
The one-sample t statistic for a test of H0: μ = 13 vs. Ha: μ < 13 based on n = 17 observations has the test
statistic value of t = −1.45. What is the p-value for this test? - (answer)pt(-1.45, 16)
A random sample of 169 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 12.11 ounces and a standard
deviation of 2.11 ounce. What is the probability that the average contents of the 169 sample cans is less
than 11.86 ounces? - (answer)pnorm(11.86, mean = 12.11, sd = 2.11/sqrt(169))
