MAT 202 CORE EXAM 2025/2026 QUESTIONS WITH
ANSWERS TAGGED A+
✔✔A random sample of 79 light bulbs had a mean life of x= 400 hours with a standard
deviation of o= 28 hours. Construct a 90 percent confi dence interval for the mean life of
all light bulbs of this type.
Let z0.05 = 1.65 and t0.05,78 = 1.66 - ✔✔C. (395: 405)
✔✔If Z is a standard normal variable, find the probability that Z is greater than -1.82
Let P(Z < 1.82) = 0.9656. - ✔✔A. 0.9656
✔✔A savings and loan association needs information regarding the checking account
balances of its local customers. A random sample of 14 accounts was checked and
yielded a mean balance of $664.14 and a standard deviation of $297.29. Find a 98%
confidence interval for the true mean checking account balance for local customers.
Assume that the population has a normal distribution.
Let z0.01 = 2.33 and t0.01,13 = 2.65 - ✔✔B. ($453.59:$874.69)
✔✔. (Choose 1 answer)
A final exam in Math 160 has a mean of 73 with standard deviation 7.8. If 24 students
are randomly selected, find the probability that the mean of their test scores is less than
70.
Let P(Z < -1.88)= 0.0301. P(Z < 1.28) = 0.8997. - ✔✔B. 0.0301
✔✔You wish to test the claim that u = 1200 at a level of significance of a = 0.01 and are
given sample statistics n = 35, the mean x=1170,s= 82. Compute the value of the test
statistic. Round your answer to two decimal places. - ✔✔A. -2.16
✔✔Suppose that the following is to be tested:
H0: p=0.72 and H1: p ≠ 0.72.
Calculate the test statistic for the following sample data: Sixty-eight out of ninety test
subjects have the characteristic of interest
Round to the nearest thousandth
(See picture) - ✔✔B. 0.751
✔✔A simple random sample of 5-year-old boys from a city is obtained and their weights
are listed below.
, 50 38 58 51 34 89 57 44 75 27 64
Use a 0.05 significance level to find the critical value to test the claim that the population
mean is smaller than 50. Assume that the population has normal distribution.
Let
Z0.025 = 1.96; t0.025,10=2.23
Z0.05 = 1.65; t0.05,10=1.81 - ✔✔B. -1.81
✔✔Using the following uniform density curve, answer the question. - ✔✔E. 0.3375
✔✔A random sample of 100 preschool children in Camperdown revealed that only 60
had confidence been vaccinated Provide an approximate 99% interval for the proportion
vaccination in that suburb.
Let z0.005 = 2.5 - ✔✔D. (0.47, 0.73)
✔✔The weekly salaries of teachers in one state are normally distributed with a mean of
$490 and a standard deviation of $45. What is the probability that a randomly selected
teach more than $525 a week?
Let P(Z < 0.78) = 0.7823. P(Z < -1.28) = 0.1003. - ✔✔B. 0.2177
✔✔According to a survey. only 15% of customers who visited the web site of a major
retail store made a purchase. Random samples of size 50 are selected. The standard
deviation of all the sample proportions of customers who will make a purchase after
visiting the web site is - ✔✔D. 0.05050
✔✔A final exam in Math 150 has a mean of 73 with standard deviation 7.8. If 24
students are randomly selected, find the probability that the mean of their test scores is
less than 70.
Let P(Z <-1.88)=0.0301, P(Z < 1.28)=0.8997. - ✔✔E 0.0301
✔✔Use the margin of error, confidence level, and standard deviation to find the
minimum sample size required to estimate an unknown population mean.
Margin of error: $126, confidence level 99%, standard deviation = $534
Let z0.05 = 2.58 - ✔✔C. 120
✔✔Suppose that the following is to be tested:
ANSWERS TAGGED A+
✔✔A random sample of 79 light bulbs had a mean life of x= 400 hours with a standard
deviation of o= 28 hours. Construct a 90 percent confi dence interval for the mean life of
all light bulbs of this type.
Let z0.05 = 1.65 and t0.05,78 = 1.66 - ✔✔C. (395: 405)
✔✔If Z is a standard normal variable, find the probability that Z is greater than -1.82
Let P(Z < 1.82) = 0.9656. - ✔✔A. 0.9656
✔✔A savings and loan association needs information regarding the checking account
balances of its local customers. A random sample of 14 accounts was checked and
yielded a mean balance of $664.14 and a standard deviation of $297.29. Find a 98%
confidence interval for the true mean checking account balance for local customers.
Assume that the population has a normal distribution.
Let z0.01 = 2.33 and t0.01,13 = 2.65 - ✔✔B. ($453.59:$874.69)
✔✔. (Choose 1 answer)
A final exam in Math 160 has a mean of 73 with standard deviation 7.8. If 24 students
are randomly selected, find the probability that the mean of their test scores is less than
70.
Let P(Z < -1.88)= 0.0301. P(Z < 1.28) = 0.8997. - ✔✔B. 0.0301
✔✔You wish to test the claim that u = 1200 at a level of significance of a = 0.01 and are
given sample statistics n = 35, the mean x=1170,s= 82. Compute the value of the test
statistic. Round your answer to two decimal places. - ✔✔A. -2.16
✔✔Suppose that the following is to be tested:
H0: p=0.72 and H1: p ≠ 0.72.
Calculate the test statistic for the following sample data: Sixty-eight out of ninety test
subjects have the characteristic of interest
Round to the nearest thousandth
(See picture) - ✔✔B. 0.751
✔✔A simple random sample of 5-year-old boys from a city is obtained and their weights
are listed below.
, 50 38 58 51 34 89 57 44 75 27 64
Use a 0.05 significance level to find the critical value to test the claim that the population
mean is smaller than 50. Assume that the population has normal distribution.
Let
Z0.025 = 1.96; t0.025,10=2.23
Z0.05 = 1.65; t0.05,10=1.81 - ✔✔B. -1.81
✔✔Using the following uniform density curve, answer the question. - ✔✔E. 0.3375
✔✔A random sample of 100 preschool children in Camperdown revealed that only 60
had confidence been vaccinated Provide an approximate 99% interval for the proportion
vaccination in that suburb.
Let z0.005 = 2.5 - ✔✔D. (0.47, 0.73)
✔✔The weekly salaries of teachers in one state are normally distributed with a mean of
$490 and a standard deviation of $45. What is the probability that a randomly selected
teach more than $525 a week?
Let P(Z < 0.78) = 0.7823. P(Z < -1.28) = 0.1003. - ✔✔B. 0.2177
✔✔According to a survey. only 15% of customers who visited the web site of a major
retail store made a purchase. Random samples of size 50 are selected. The standard
deviation of all the sample proportions of customers who will make a purchase after
visiting the web site is - ✔✔D. 0.05050
✔✔A final exam in Math 150 has a mean of 73 with standard deviation 7.8. If 24
students are randomly selected, find the probability that the mean of their test scores is
less than 70.
Let P(Z <-1.88)=0.0301, P(Z < 1.28)=0.8997. - ✔✔E 0.0301
✔✔Use the margin of error, confidence level, and standard deviation to find the
minimum sample size required to estimate an unknown population mean.
Margin of error: $126, confidence level 99%, standard deviation = $534
Let z0.05 = 2.58 - ✔✔C. 120
✔✔Suppose that the following is to be tested:
