Hypothesis Testing One Sample

A recruiter for the Super Teachers School Board advertised that the average teacher's salary in a certain competing district is less than what his district offers, $50,000. A random sample of 50 teachers from the competing district had a mean annual salary of $48,300. The population standard deviation is known to be $8,000. Use a 0.01 level of significance to test the recruiter's claim.

What is the p-value? Round to 4 decimal places!!

A recruiter for the Super Teachers School Board advertised that the average teacher's salary in a certain competing district is less than what his district offers, $50,000. A random sample of 50 teachers from the competing district had a mean annual salary of $48,300. The population standard deviation is known to be $8,000. Use a 0.01 level of significance to test the recruiter's claim. Choose the correct conclusion.

• There is enough evidence to support the claim that the average teacher's salary in the competing district is less than $50,000.

• There is not enough evidence to support the claim that the average teacher's salary in the competing district is less than $50,000.

• There is enough evidence to support the claim that the average teacher's salary in the competing district is more than $50,000.

• There is not enough evidence to support the claim that the average teacher's salary in the competing district is more than $50,000.

Environmental advocates believe that there is too much Mercury in a town's lake. To test their claim, they took 7 samples of water from the lake and measured the concentration of mercury, in milligrams per cubic meter, in each sample. Assume the population distribution is normal. The sample results were: 1.02, 1.23, 0.91, 1.29, 1.01, 1.35, 1.43 Perform a hypothesis test to determine if the mean concentration of mercury is greater than 1 milligram per cubic meter. Use a 0.05 level of significance. Choose the correct null and alternate hypothesis statements.

Environmental advocates believe that there is too much Mercury in a town's lake. To test their claim, they took 7 samples of water from the lake and measured the concentration of mercury, in milligrams per cubic meter, in each sample. Assume the population distribution is normal. The sample results were: 1.02, 1.23, 0.91, 1.29, 1.01, 1.35, 1.43 Perform a hypothesis test to determine if the mean concentration of mercury is greater than 1 milligram per cubic meter. Use a 0.05 level of significance. What type of test should you run?

• Z test

• T test

• 1-Prop Z test

• X² test

Environmental advocates believe that there is too much Mercury in a town's lake. To test their claim, they took 7 samples of water from the lake and measured the concentration of mercury, in milligrams per cubic meter, in each sample. Assume the population distribution is normal. The sample results were: 1.02, 1.23, 0.91, 1.29, 1.01, 1.35, 1.43 Perform a hypothesis test to determine if the mean concentration of mercury is greater than 1 milligram per cubic meter. Use a 0.05 level of significance. What is your decision?

• Reject the Null

• Fail to Reject the Null

• Accept the Null

Environmental advocates believe that there is too much Mercury in a town's lake. To test their claim, they took 7 samples of water from the lake and measured the concentration of mercury, in milligrams per cubic meter, in each sample. Assume the population distribution is normal. The sample results were: 1.02, 1.23, 0.91, 1.29, 1.01, 1.35, 1.43 Perform a hypothesis test to determine if the mean concentration of mercury is greater than 1 milligram per cubic meter. Use a 0.05 level of significance. Choose the correct conclusion statement

• There is not enough evidence to conclude that the mean concentration of mercury in the town lake is greater than 1 milligram.

• There is not enough evidence to conclude that the mean concentration of mercury in the town lake is less than 1 milligram.

• There is enough evidence to conclude that the mean concentration of mercury in the town lake is less than 1 milligram.

• There is enough evidence to conclude that the mean concentration of mercury in the town lake is greater than 1 milligram.

The average miles on a tank of gas for the Ford

Explorer is 300 miles with a standard deviation of 22

miles. A consumer group feels the average is actually

lower. They survey 40 vehicles and find the average

miles per tank is 290 miles. At α = 0.05, test the

consumer groups’ claim that the miles per tank is

actually lower than 300 miles.

• Reject Ho

• Reject Ha

• Fail to reject Ho

• Fail to reject Ha

A sample of 35 cans of Campbell’s Tomato Soup found

that the net weight of the cans was 298 grams with a

standard deviation of 24 grams. The production line

supervisor has been told that the net weight of all cans

is 308 grams. Is there enough evidence, at the 5% level,

to say that the weight of the cans is something other

than 308 grams?

• Reject Ho

• Reject Ha

• Fail to reject Ho

• Fail to reject Ha

The Quick Stop claims that the Big Slurp will contain 48

ounces of drink. You decide to test this claim because

you feel the actual amount is lower. Over the next few

weeks, you buy 50 Big Slurps and find the average

amount of drink is 47 ounces with a standard deviation

of 2.75 ounces. At α = 0.05, can you reject the Quick

Stop’s claim?

• Reject Ho

• Reject Ha

• Fail to reject Ho

• Fail to reject Ha

A cereal company claims the mean sodium content in

one serving of its cereal is no more than 230 mg. You

work for a national health service and are asked to test

this claim. You find that a random sample of 52

servings has a mean sodium content of 232 mg and a

standard deviation of 10 mg. At α = 0.05, do you have

enough evidence to reject the company’s claim?

• Reject Ho

• Reject Ha

• Fail to reject Ho

• Fail to reject Ha