Preparing to Test a Claim about a Mean assignment

A manufacturer of a specific make and model of car claims that the average highway fuel economy is 32 mpg. A skeptical consumer group believes that this may be an overstatement. They select a random sample of 10 cars of this make and model and find that the sample mean number of miles per gallon is 28, with a standard deviation of 8.3 mpg. The distribution of the sample shows no skewness or outliers. Check the three conditions for this t test for one mean.

10 cars of this make and model all cars of this make and model 10 is small shows no skewness or outliers

tA drink dispenser at a restaurant is programmed to dispense 20 ounces of beverage when the "medium" button is pressed. There is some variability in amount dispensed. An inspector selects a random sample of 30 beverages filled by the machine and measures the contents. The mean amount of beverage dispensed was 18.5 ounces, with a standard deviation of 0.75 ounces. The inspector would like to know if these data provide convincing evidence that the true mean amount dispensed when the medium button is pressed differs from 20 ounces. What is the value of the standardized test statistic and P-value? If needed, use the t-table to answer the question. Check all that apply.

A C F

credit-card company reports that its customers' average monthly balance is $10,200. A random sample of 25 customers reveals an average monthly balance of $15,100, with a standard deviation of $6,200. A test will be conducted to determine whether there is convincing evidence to conclude that the mean monthly balance is greater than the credit-card company claims. μ = the true mean monthly balance for all customers of this credit-card company What are the null and alternative hypotheses for this test?

H0: μ = $10,200 Ha: μ > $10,200

A manufacturer of a specific make and model of car claims that the average highway fuel economy is 32 mpg. A skeptical consumer group believes that this may be an overstatement. μ = the true mean highway fuel economy for all cars of this make and model = the mean highway fuel economy for the sample of cars that are tested What are the null and alternative hypotheses for this test?

H0: μ = 32 mpg Ha: μ < 32 mpg

A drink dispenser at a restaurant is programmed to dispense 20 ounces of beverage when the "medium" button is pressed. There is some variability in amount dispensed. An inspector selects a random sample of 30 beverages filled by the machine and measures the contents. The mean amount of beverage dispensed was 18.5 ounces, with a standard deviation of 0.75 ounces. The inspector would like to know if these data provide convincing evidence that the true mean amount dispensed when the medium button is pressed differs from 20 ounces. What are the null and alternative hypotheses for this test?

equals 20 ounces is different from 20 ounces amount of beverage dispensed 20-ounce beverages

A drink dispenser at a restaurant is programmed to dispense 20 ounces of beverage when the "medium" button is pressed. There is some variability in amount dispensed. An inspector selects a random sample of 30 beverages filled by the machine and measures the contents. The mean amount of beverage dispensed was 18.5 ounces, with a standard deviation of 0.75 ounces. The inspector would like to know if these data provide convincing evidence that the true mean amount dispensed when the medium button is pressed differs from 20 ounces. The P-value of this test is approximately 0. What conclusion should be made? Use = 0.05.

less than reject have different from

A manufacturer of a specific make and model of car claims that the average highway fuel economy is 32 mpg. A skeptical consumer group believes that this may be an overstatement. They select a random sample of 10 cars of this make and model and find that the sample mean number of miles per gallon is 27, with a standard deviation of 5.3 mpg. The distribution of the sample shows no skewness or outliers. Do the data provide convincing evidence that the true mean highway fuel economy is less than 32 mpg? The P-value of this test is between 0.005 and 0.01. What conclusion should be made? Use = 0.01.

less than reject have less than

A manufacturer of a specific make and model of car claims that the average highway fuel economy is 32 mpg. A skeptical consumer group believes that this may be an overstatement. They select a random sample of 10 cars of this make and model and find that the sample mean number of miles per gallon is 27, with a standard deviation of 5.3 mpg. The distribution of the sample shows no skewness or outliers. Do the data provide convincing evidence that the true mean highway fuel economy is less than 32 mpg? What is the value of the standardized test statistic and P-value? If needed, use the t-table to answer the question.

t = -2.98; 0.005 < P-value < 0. 01

A drink dispenser at a restaurant is programmed to dispense 20 ounces of beverage when the "medium" button is pressed. There is some variability in amount dispensed. An inspector selects a random sample of 30 beverages filled by the machine and measures the contents. The mean amount of beverage dispensed was 18.5 ounces, with a standard deviation of 0.75 ounces. The inspector would like to know if these data provide convincing evidence that the true mean amount dispensed when the medium button is pressed differs from 20 ounces. Name the test:

t test for one mean medium beverages all medium beverages the sample size is at least 30