Questions from Statistics Principles

Q: A Bernoulli random variable is a variable that is either 0 (

A Bernoulli random variable is a variable that is either 0 (a failure) or 1 (a success). The probability of success is denoted p. (a) Use a statistical spreadsheet to generate 1000 Bernoulli samples o...

Q: Jane wants to estimate the proportion of students on her campus who

Jane wants to estimate the proportion of students on her campus who eat cauliflower. After surveying 20 students, she finds 2 who eat cauliflower. Obtain and interpret a 95% confidence interval for th...

Q: A school board at a local community college is considering raising the

A school board at a local community college is considering raising the student services fees. The board wants to obtain the opinion of the student body before proceeding. Design a sampling method to o...

Q: Alan wants to estimate the proportion of adults who walk to work

Alan wants to estimate the proportion of adults who walk to work. In a survey of 10 adults, he finds 1 who walks to work. Explain why a 95% confidence interval using the normal model yields silly resu...

Q: The American Society for Microbiology (ASM) and the Soap and

The American Society for Microbiology (ASM) and the Soap and Detergent Association (SDA) jointly commissioned two separate studies, both of which were conducted by Harris Interactive. In one of the st...

Q: Explain what “95% confidence” means in a 95%

Explain what “95% confidence” means in a 95% confidence interval.

Q: What type of variable is required to construct a confidence interval for

What type of variable is required to construct a confidence interval for a population proportion?

Q: Explain why quadrupling the sample size causes the margin of error to

Explain why quadrupling the sample size causes the margin of error to be cut in half.

Q: Why do polling companies often survey 1060 individuals when they wish to

Why do polling companies often survey 1060 individuals when they wish to estimate a population proportion with a margin of error of 3% with 95% confidence?

Q: Katrina wants to estimate the proportion of adult Americans who read at

Katrina wants to estimate the proportion of adult Americans who read at least 10 books last year. To do so, she obtains a simple random sample of 100 adult Americans and constructs a 95% confidence in...