Study Guide Unit 11 Statistics

Match the following

• Convenience Sampling

• Only subjects that are nearby or easy to get to are chosen.

• Control Group

• data that fall into categories, or that indicate a qualitative rather than quantitative attribute

• Categorical Variable

• a group of subjects who are not exposed to the variable under study

• Cluster Sampling

• A population is divided into clusters and entire clusters are chosen as the sample

• Bias

• a systematic error in a study caused by the sampling method

Match the following

• numerical data that can be compared, added, subtracted or otherwise operated on

• Systematic Sampling

• involves applying a treatment to some group or groups and measuring the effects of treatment

• Statistical Variable

• quantity or quality that can be measured or counted

• Parameter

• A rule is used to select members of a sample.

• Experiment

• a measure that describes a population

• Quantitative Variable

Researchers randomly choose two groups from 16 volunteers. Over a period of 10 weeks, one group

watches television before going to sleep, and the other does not. Volunteers wear monitoring devices while

sleeping, and researchers record dream activity. Which type of study method is described in each situation?

• survey

• controlled experiment

• observational study

The scores on an exam are normally distributed, with a mean of 77 and a standard deviation of 7. What

percent of the scores are greater than 84?

• 84%

• 16%

• 68%

• 2.5%

Why is the following a statistical question?

How many plays do students see in a year?

• Different students can see different

  numbers of plays in a year.

• Some students might not see any plays in

  a year.

• The question asks about only one year.

• Some students might not like seeing

  plays.

List the mean, standard deviation, and five-number summary of the following data set. Use a spreadsheet to

calculate the standard deviation.

6, 10, 14, 3, 8, 10, 3, 6, 9, 6

• mean: 8.3; standard deviation: 3.2

  min: 3; Q1: 6; median: 7; Q3: 10; max: 14

• mean: 7.5; standard deviation: 3.2

  min: 3; Q1: 6; median: 8.3; Q3: 10; max: 14

• mean: 7.5; standard deviation: 3.6

  min: 3; Q1: 6; median: 7; Q3: 10; max: 14

List the mean, standard deviation, and five-number summary of the following data set. Use a spreadsheet to

calculate the standard deviation.

12, 10, 13, 14, 9, 6, 6, 6, 4, 7

• mean: 8.7; standard deviation: 3.6

  min: 4; Q1: 6; median: 8; Q3: 12; max: 14

• mean: 8.7; standard deviation: 3.3

  min: 4; Q1: 6; median: 9.7; Q3: 12; max: 14

• mean: 9.7; standard deviation: 3.3

  min: 4; Q1: 6; median: 8; Q3: 12; max: 14

Write a statistical question that uses a categorical variable.

• How much do you spend on groceries

  each month?

• How many words do you actively use

  on average?

• What is your favorite primary color?

• How much change do you have in your

  pocket?

The numbers of cookies in a shipment of bags are normally distributed, with a mean of 63 and a standard

deviation of 3. What percent of bags of cookies will contain between 57 and 69 cookies?

• 47.5%

• 2.5%

• 95%

• 16%

To investigate a community’s reading habits, a publication invites readers to complete and mail in a survey.

What type of sampling method is this?

• self-selected

• random

• systematic

• convenience