Statistics Data Analysis

Which of the following is an example of a categorical variable?

• the weight of a backpack

• the proportion of backpacks that weigh more than 50 pounds

• the type of backpack used

• the number of books in a backpack

All the residents of a building were polled about whom they would vote for in the upcoming city election for comptroller. What are the sample and the population in this poll?

• The population is the residents of the building; the sample is the residents who responded.

• The population is the registered voters in the city; the sample is the residents of the building.

• The population is the residents of the building; the sample is the registered voters in the city

• The population is the registered voters in the city; the sample is a random sample of the residents of the building.

A census reports that the mean retirement age is 68.3 years. In a random sample, the mean retirement age is 65.8 years. What is the mean of 65.8 years?

• a parameter

• a statistic

• a variable

• a sample

Which of the following types of sampling are not biased? Select all that apply.

• cluster

• convenience

• self-selected

• stratified

• systematic

A student polls randomly-selected students in his school to see what kinds of music they like. What type of study is described?

• a sample survey

• an experiment

• an observational study

• a cluster study

A list of basketball players is divided into groups by the alphabetical order of the players’ last names, and then one group is used as a sample for a survey. What kind of sampling method is used?

• convenience sampling

• systematic sampling

• cluster sampling

• stratified sampling

A data set is normally distributed with a mean of 25 and a standard deviation of 1.5. Find the z-score for a value of 20,

to the nearest hundredth.

• -3.33

• 2.54

• -4.01

• 3.37

A data set is normally distributed with a mean of 25 and a standard deviation of 1.5. About what percent of the data is

greater than 26? (Hint: use normalcdf)

• 48%

• 25%

• 4%

• 0.2%

Data Set A: 1 1 3 5 0 0 4 1 0 1 4

Data Set B: 2 1 4 5 1 1 3 6 5 3 1

Data Set A is ____________________.

• symmetrical

• skewed right

• skewed left

Data Set A: 1 1 3 5 0 0 4 1 0 1 4

Data Set B: 2 1 4 5 1 1 3 6 5 3 1

Data Set B is _______________.

• symmetrical

• skewed right

• skewed left