Questions from Statistics Principles

Q: Surveys tend to suffer from low response rates. Based on past

Surveys tend to suffer from low response rates. Based on past experience, a researcher determines that the typical response rate for an e-mail survey is 40%. She wishes to obtain a sample of 300 respo...

Q: A political scientist wants to know how a random sample of 18

A political scientist wants to know how a random sample of 18- to 25-year-olds feel about Democrats and Republicans in Congress. She obtains a random sample of 1030 registered voters 18 to 25 years of...

Q: An educator wants to determine whether a new curriculum significantly improves standardized

An educator wants to determine whether a new curriculum significantly improves standardized test scores for third grade students. She randomly divides 80 third-graders into two groups. Group 1 is taug...

Q: A psychologist wants to know whether subjects respond faster to a go

A psychologist wants to know whether subjects respond faster to a go/no go stimulus or a choice stimulus. With the go/no go stimulus, subjects must respond to a particular stimulus by pressing a butto...

Q: Test whether / /

Test whether / /

Q: Test whether / /

Test whether / /

Q: Test whether / /

Test whether / /

Q: Test whether / /

Test whether / /

Q: x1 = 368, n1 = 541, x2 = 421,

x1 = 368, n1 = 541, x2 = 421, n2 = 593, 90% confidence

Q: x1 = 109, n1 = 475, x2 = 78,

x1 = 109, n1 = 475, x2 = 78, n2 = 325, 99% confidence