Statistics Type of Studies

The measure of average which include all the observations in a data.

• Median

• Mode

• Mean

Inferential vs descriptive statistics:

Draws educated conclusions about a population that is likely too large to sample completely

• Descriptive

• Inferential

The police department tracked the number of ticket writers and number of tickets issued for the past 8 weeks.  The scatter plot shows the results.  Which statement is true?

• More ticket writers results in fewer tickets issued.

• There were 50 tickets issued every week.

• When there are 10 ticket writers, there will be 800 tickets issued.

• More ticket writers results in more tickets issued.

A teacher wants to know the average time spent doing homework by the students in her class of 20 girls and 5 boys.
She selects the five closest to her desk.

• simple random

• Voluntary Response

• Convenience

• Systematic Random

An independent research company wants to go door to door to survey people in the city of Fontana. The company decides to number all blocks within the city limit, randomly choose 50 blocks and survey all households on each selected block. 
This is an example of:

• Simple Random Sample

• Stratified Random Sample

• Cluster Random Sample

• Systematic Random Sampling

To study the amount of time students spend doing homework each day, use a random number generator to select 25 students from the student enrollment database to survey.

• Convenience Sample

• Simple Random Sample

• Stratified Random Sample

• Interval Sample

A recent survey found that out of 400 random American adults, 89% pay their bills on time. The margin of error in this survey was 2%. What is the interval of values in which the truth is likely found?

• 89% - 91%

• 87% - 89%

• 87% - 91%

• 388 - 402

A recent survey found that 77% of high schoolers use their phones more than 4 hours a day on average. The margin of error was 3%. What is the interval for which we could expect to find the truth of the population?

• 77% - 80%

• 74% - 77%

• 74% - 80%

• 50 million high schoolers - 120 million

Disneyland often surveys its guests as they exit a restaurant during their visit. The surveyor stands at the restaurant exit, counts the number of people leaving, and surveys every 25th guest.
This is a form of:

• Random Sample

• Convenience Sampling

• Voluntary Response

• Systematic Sampling

You want to see if fifth-grade boys or fifth-grade girls are faster at solving jigsaw puzzles. You randomly select twenty fifth-grade boys and twenty fifth-grade girls from fifth graders in your school district. You time and record how long it takes each student to solve the same jigsaw puzzle correctly.

• Survey

• Experimental Study

• Observational Study