Statistics

Statistics

Biased & Unbiased

• Population - an entire group

• Sample - a part of the population

• Random Sample - members of the population are chosen at random

• Convenience Sample - members of the population that are readily available

• BIASED SAMPLE - does not fairly represent the population.

Lets look at

Biased and Unbiased samples

Multiple Choice

Ana wants to know the average student’s opinion of the tardy policy at her school. Which group of students should she survey in order to achieve the most accurate results?

• thirty students who are often tardy
• thirty students who are rarely tardy
• thirty of her friends
• thirty randomly selected students from her school

Multiple Choice

At an assembly 7 out of 10 students who entered the gym were carrying a backpack. Based on this information, if 700 students were at the assembly, how many students could be expected to be carrying a backpack?

• 49

• 490

• 210

• 421

Multiple Choice

To determine the most popular children’s programs, a television station asks parents to call in and complete a phone survey.

• Biased Sample

• Unbiased Sample

Multiple Choice

To evaluate the defect rate of its memory chips, an integrated circuit manufacturer tests every 100th chip off the production line.

• Biased Sample

• Unbiased Sample

Multiple Choice

Define bias.

• tolerance
• two sided
• in favor of one side
• hate

Multiple Choice

The quality of being believable or trustworthy is called? 

• Credibility
• Evidence
• Support
• Cite

Multiple Choice

A solid and reasonable argument that opposes or disagrees with your claim

• claim
• counterclaim
• support
• rebuttal

Multiple Choice

What is an unbiased resource?

• source not cited
• unfair
• cited source
• neutral or fair; 

Making inferences with collected data.

Making predictions based on data

• Random sampling

Multiple Choice

• A

• B

• C

• D

Fill in the Blank

The Student Council asked every tenth student in the lunch line how they preferred to be contacted with school news. The results are shown in the table. Suppose there are 684 students at the school. How many can be expected to prefer E-mail? (just type in the number)

Fill in the Blank

A bank randomly surveyed 50 of its customers by mail to find out how customers use its mobile banking service. The survey found that only 11 of the 50 customers used the service.

If the branch has 1,700 customers, about _____ customers use the mobile banking service.

*Only type in the numerical answer.

Multiple Choice

Zoie completes a report by asking 70 students across campus. She found that 48% of CIAA students do not wash their hands after using the bathroom. What is the sample size?

• 48

• 100

• 70

• CIAA students