AP Statistics 9.1 and 9.2

Experiments on learning in animals sometimes

measure how long it takes mice to find their way

through a maze. The mean time is 18 seconds for

one particular maze. A researcher thinks that a loud

noise will cause the mice to complete the maze

faster. She measures how long each of 10 mice takes

with a noise as stimulus. The appropriate hypotheses

for the significance test are

• finds convincing evidence that a majority of residents supports the tax increase, when in reality there isn’t convincing evidence that a majority supports the increase.

• finds convincing evidence that a majority of residents supports the tax increase, when in reality at most 50% of city residents support the increase.

• finds convincing evidence that a majority of residents supports the tax increase, when in reality more than 50% of city residents do support the increase.

• does not find convincing evidence that a majority of residents supports the tax increase, when in reality more than 50% of city residents do support the increase.

• does not find convincing evidence that a majority of residents supports the tax increase, when in reality at most 50% of city residents do support the increase.

• Only 18% of the city residents support the tax increase.

• There is an 18% chance that the majority of residents

  supports the tax increase.

• Assuming that 50% of residents support the tax

  increase, there is an 18% probability that the sample

  proportion would be 0.527 or higher by chance alone.

• Assuming that more than 50% of residents support the

  tax increase, there is an 18% probability that the sample

  proportion would be 0.527 or higher by chance alone.

• Assuming that 50% of residents support the tax

  increase, there is an 18% chance that the null

  hypothesis is true by chance alone.

After once again losing a football game to the

archrival, a college’s alumni association conducted

a survey to see if alumni were in favor of firing the

coach. An SRS of 100 alumni from the population

of all living alumni was taken, and 64 of the alumni

in the sample were in favor of firing the coach. Sup-

pose you wish to see if a majority of living alumni

are in favor of firing the coach. The appropriate test

statistic is

Which of the following is not a condition for

performing a significance test about a population

proportion p?

• The data should come from a random sample or

  randomized experiment.

• If you are sampling without replacement from a finite population, then you should sample no more than 10% of the population.

• The population distribution should be approximately Normal, unless the sample size is large.

• All of the above are conditions for performing a significance test about a population proportion.

• inconclusive because we don't know the value of p-hat

• (0.19, 0.27)

• (0.24, 0.30)

• (0.27, 0.31)

• (0.29, 0.38)

• None of these

The reason we use t procedures instead of z procedures when carrying out a test about a population mean is that

• z requires that the sample size be large.

• z requires that the data come from a random sample or randomized experiment.

• z requires that the population distribution be perfectly Normal.

• z can only be used for proportions.

• falls between 0.01 and 0.02.

• falls between 0.02 and 0.04.

• falls between 0.04 and 0.05.

• falls between 0.05 and 0.25.

• is greater than 0.25.