Hi there,
I have this assignment question pertaining to confidence intervals and I have to admit that I am a little lost in this class and I have no idea where to get started. If someone could give me an idea of how to solve it or guide me through it, that would be great. Thanks!
b. The survey reported that 31% of the respondents feel they have to save more for retirement to make up for what they lost. Develop a 95% confidence interval for the population proportion.
c. Five percent of the respondents gave $25,000 or more to charity over the previous year. Develop a 95% confidence interval for the proportion who gave $25,000 or more to charity.
d. Compare the margin of error for the interval estimates in parts (a), (b), and (c). How is the margin of error related to ? When the same sample is being used to estimate a variety of proportions, which of the proportions should be used to choose the planning value p? Why do you think p = .50 is often used in these cases?
I have this assignment question pertaining to confidence intervals and I have to admit that I am a little lost in this class and I have no idea where to get started. If someone could give me an idea of how to solve it or guide me through it, that would be great. Thanks!
- A Phoenix Wealth Management/Harris Interactive survey of 1,500 individuals with net worth of $1 million or more provided a variety of statistics on wealthy people (Business Week, September 22, 2003). The previous three-year period had been bad for the stock market, which motivated some of the questions asked.
b. The survey reported that 31% of the respondents feel they have to save more for retirement to make up for what they lost. Develop a 95% confidence interval for the population proportion.
c. Five percent of the respondents gave $25,000 or more to charity over the previous year. Develop a 95% confidence interval for the proportion who gave $25,000 or more to charity.
d. Compare the margin of error for the interval estimates in parts (a), (b), and (c). How is the margin of error related to ? When the same sample is being used to estimate a variety of proportions, which of the proportions should be used to choose the planning value p? Why do you think p = .50 is often used in these cases?