5.1
The sum of all the probabilities in a discrete probability distribution must be equal to
1
6.1 Question 1
0.803
The mean serum cholesterol level for U.S. adults was 196, with a standard deviation of 36 (the units are milligrams per deciliter). A simple random sample of 104 adults is chosen. Use the TI-84 calculator. What is the probability that the sample mean cholesterol level is greater than 205? Round the answers to four decimal places.
0.0054
If n is the sample size and x is the number in the sample who have a certain characteristic, then x over n is called the sample
A.) Distribution
B.) Proportion
C.) Population
D.) Mean
B.) Proportion
5.1 Question 2
.86
Use the TI-84 Plus calculator to find the z -score for which the area to its left is 0.78. Round the answer to two decimal places.
0.77
The mean serum cholesterol level for U.S. adults was 196, with a standard deviation of 36 (the units are milligrams per deciliter). A simple random sample of 104 adults is chosen. Use the TI-84 calculator. What is the probability that the sample mean cholesterol level is between 187 and 194? Round to 4 decimals.
0.2801
According to the Internal Revenue Service, the proportion of federal tax returns for which no tax was paid was p = 0.326. As part of a tax audit, tax officials draw a simple random sample of n = 140 tax returns. Use the TI-84 Plus calculator as needed.
What is the probability that the sample proportion of tax returns for which no tax was paid is less than 0.29? Round the answer to at least four decimal places.
0.1814
5.1 Question 3
.65
A normal population has mean μ = 39 and standard deviation σ = 10. What proportion of the population is between 17 and 28?
0.1349
Assume that in a given year the mean mathematics SAT score was 550 and the standard deviation was 124. A sample of 69 scores is chosen. Use the TI-84 Plus calculator.What is the probability that the sample mean score is less than 533? Round the answer to at least four decimal places.
0.1274
According to the Internal Revenue Service, the proportion of federal tax returns for which no tax was paid was p = 0.326. As part of a tax audit, tax officials draw a simple random sample of n = 140 tax returns. Use the TI-84 Plus calculator as needed.
What is the probability that the sample proportion of tax returns for which no tax was paid is between 0.36 and 0.43? Round the answer to at least four decimal places.
0.1965
5.1 Question 4
All probabilities are between 0 and 1, and all probabilities add up to 1.
A normal population has mean μ = 52 and standard deviation σ = 12. Find the value that has 30% of the population above it. Use the TI-84 Plus calculator as needed. Round the answer to one decimal place.
58.3
The mean monthly rent for a one-bedroom apartment without a doorman in Manhattan is $2643. Assume the standard deviation is $502. A real estate firm samples 102 apartments. Use the TI-84 Plus calculator.What is the probability that the sample mean rent is between $2512 and $2600? Round the answer to at least four decimal places.
0.1893
According to the Internal Revenue Service, the proportion of federal tax returns for which no tax was paid was p = 0.326. As part of a tax audit, tax officials draw a simple random sample of n = 140 tax returns. Use the TI-84 Plus calculator as needed.
What is the probability that the sample proportion of tax returns for which no tax was paid is greater than 0.32? Round the answer to at least four decimal places.
0.5596
5.1 Question 5
The weight of male babies less than 2 months old in the United States is normally distributed with mean 11.6 and standard deviation 2.9. Use the TI-83 Plus/TI-84 Plus calculator to answer the following. Round the answers to 4 decimal places. What proportion of babies weigh more than 12 pounds?
0.4451
The length of film screenings at an independent cinema has a mean of 52.1 minutes and a standard deviation of 12.9 minutes. A sample of 115 screenings is studied. Use the TI-84 Plus calculator as needed. Find the probability that the mean length of this sample is between 48.7 and 54.2. Round the answers to at least four decimal places.
0.9572
According to the Internal Revenue Service, the proportion of federal tax returns for which no tax was paid was p = 0.326. As part of a tax audit, tax officials draw a simple random sample of n = 140 tax returns. Use the TI-84 Plus calculator as needed.
Using a cutoff of 0.05, would it be unusual if the sample proportion of tax returns for which no tax was paid was less than 0.23?
0.0087.
Yes