AP Statistics - Chapter 7 Review

At a particular college, 78% of students are receiving some kind of financial aid. The school newspaper selects a random sample of 1000 students and 72% of the respondents say they are receiving some sort of financial aid. Which of the following statements is true?

• 78% is a population and 72% is a sample.

• 72% is a population and 78% is a sample.

• 78% is a parameter and 72% is a statistic.

• 72% is a parameter and 78% is a statistic.

• 78% is a parameter and 100 is a statistic.

A statistic is an unbiased estimator of a parameter when...

• The statistic is calculated from a random sample.

• The single sample, the value of the statistic is equal to the value of the parameter.

• In many samples, the values of the statistic are very close to the value of the parameter.

• In many samples, the values of the statistic are centered at the value of the parameter.

• In many samples, the distribution of the statistic has a shape that is approximately Normal.

What is distribution of values taken by a statistic in all possible samples of the same size in all possible samples of the same size from the same population called?

• The probability that the statistic is obtained.

• The population parameter.

• The variance of the values.

• The sampling distribution of the statistic.

• The distribution of sample data.

If the mean statistic of a sampling distribution is equal to the true value of parameter being estimated, what is the statistic said to be?

• Unbiased

• Proportion

• Biased

• Varied

• Random

Increasing the sample size of an opinion poll will reduce the...

• Bias of the estimates made from the data collected in the poll.

• Variability of the estimates made from the data collected in the poll.

• Effect of nonresponse on the poll

• Variability of opinions in the sample.

• Variability of opinions in the population.

What condition must be verified before finding the standard deviation (shown below) of the sampling distribution of the sample mean?

• n > 30

• np > 10 and n(1 - p) > 10

• the sample size is less than 10% of the population size

• the population's distribution is approximately normal

• no conditions must be met

Which of the following conditions must be met before finding the standard deviation (pictured below) of the sampling distribution of the sample proportion?

• n > 30

• np > 10 and n(1 - p) > 10

• the sample is less than 10% of the population size

• the population's distribution is approximately normal

• no conditions must be met

Which of the following conditions must be met in order to assess Normality for a sampling distribution of the sample mean?

• n > 30

• np > 10 and n(1 - p) > 10

• the sample size is less than 10% of the population size

• the population's distribution is approximately normal

• a or d

Which of the following conditions must be met in order to assess Normality for a sampling distribution of a sample proportion?

• n > 30

• np > 10 and n(1 - p) > 10

• the sample size is less than 10% of the population size

• the population's distribution is approximately normal

The magazine Sports Illustrated asked a random sample of 750 D1 athletes, "Do you believe sports performance enhancing drugs are a problem in college sports?" Suppose that 30% of all D1 athletes think that these drugs are a problem. Let p-hat be the sample proportion who say that these drugs are a problem. Which of the following are the mean and standard deviation?

• mean = 0.30 and SD = 0.0117

• mean = 0.30 and SD = 0.55

• mean = 0.30 and SD = 0.0003

• mean = 225 and SD = 12.5

• mean = 225 & SD = 157.5