AP Unit 5 Quiz Review

What is a parameter?

• a number that describes some characteristic of the population

• a number that describes some characteristic of a sample

• A sample

• A population

What is a statistic?

• A sample

• a number that describes some characteristic of the population

• A population

• a number that describes some characteristic of a sample

What is the mean of a sample/statistic?

• x

• x bar

• mu

• sigma

What is the mean of a population/parameter?

• x bar

• x

• mu

• sigma

What is a sampling variability?

• the value of a statistic varies in repeated random sampling

• It is a distribution of numbers

• the distribution of values taken by the statistic in all possible samples of the same size from the same population

What are the 3 distinct distributions involved when we sample repeatedly and measure a variable of interest?

• 1) The population distribution gives the values of the variable for all the individuals in the population

  2) The distribution of a sample data shows the values of the variable for all the individuals in the sample

  3) The sampling distribution shows the statistic values from all the possible samples of the same size from the population

• 1)The sampling distribution gives the values of the variable for all the individuals in the sample

  2) The distribution of a population data shows the values of the variable for all the individuals in the population

  3) The population distribution shows the statistic values from all the possible samples of the same size from the population

• 1)The population distribution gives the values of the variable for all the individuals in the sample

  2) The distribution of a population data shows the values of the variable for all the individuals in the population

  3) The sampling distribution shows the statistic values from all the possible samples of the same size from the population

Larger samples sizes _______ variability

• higher

• lower

• same

Answer explanation

Low variability is better, it has a tighter distribution

At a particular college, 78% of all students are receiving some kind of financial aid. The school newspaper selects a random sample of 100 students and 72% of the respondents say they are receiving some sort of financial aid. Which of the following is true?

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

• (b) 72% is a population and 78% is a sample.

• (c) 78% is a parameter and 72% is a statistic.

• (e) 78% is a parameter and 100 is a statistic.

Which of the following statements about the sampling distribution of the sample mean is incorrect?

• (a) The standard deviation of the sampling distribution will decrease as the sample size increases.

• (e) The sampling distribution shows how the sample was distributed around the sample mean.

• (d) The sampling distribution shows how the sample mean will vary in repeated samples.

• (b) The standard deviation of the sampling distribution is a measure of the variability of the sample mean among repeated samples.

• (c) The sample mean is an unbiased estimator of the population mean.

Which of the following distributions has a mean that varies from sample to sample?

i. The population distribution

ii. The distribution of sample data

iii. The sampling distribution

• a. i only

• b. ii only

• c. iii only

• d. ii and iii

• e. i, ii, and iii