8. Sampling Distributions & Confidence Intervals: Proportion

"In Problems 23 through 26, indicate whether a confidence interval for a proportion or mean should be constructed to estimate the value of the variable of interest. Justify your response.

A researcher wanted to know whether consumption of green tea on a daily basis reduces LDL (bad) cholesterol. She obtains a random sample of 500 subjects. Each subject consumes at least 1 cup of green tea daily for 1 year. After 1 year, the researcher determines whether the subjects LDL cholesterol decreased, or not."

"In Problems 23 through 26, indicate whether a confidence interval for a proportion or mean should be constructed to estimate the value of the variable of interest. Justify your response.

Does chewing your food for a longer period of time reduce one’s caloric intake of food at dinner? A researcher requires a sample of 75 healthy males to chew their food twice as long as they normally do. The researcher then records the calorie consumption at dinner."

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

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

[NW] You Explain It! New Deal Policies In response to the Great Depression, Franklin D. Roosevelt enacted many New Deal policies. One such policy was the enactment of the National Recovery Administration (NRA), which required businesses to agree to wages and prices within their particular industry. The thought was that this would encourage higher wages among the working class, thereby spurring consumption. In a Gallup survey conducted in 1933 of 2025 adult Americans, 55% thought that wages paid to workers in industry were too low. The margin of error was 3 percentage points with 95% confidence. Which of the following represents a reasonable interpretation of the survey results? For those that are not reasonable, explain the flaw.

b. We are 92% to 98% confident 55% of adult Americans during the Great Depression felt wages paid to workers in industry were too low.