How many widgets need to be sampled in order to be 98% confident that the error in estimating the true proportion of defective widgets is at most 0.05? Assume you have no idea what the true proportion is.

For this problem, carry at least four digits after the decimal in your calculations. Answers may vary slightly due to rounding.The National Council of Small Businesses is interested in the proportion of small businesses that declared Chapter 11 bankruptcy last year. Since there are so many small businesses, the National Council intends to estimate the proportion from a random sample. Let p be the proportion of small businesses that declared Chapter 11 bankruptcy last year.

Suppose that for a test of proportion we have :p=0.5 and . The test statistic z=1.53 and the p-value is reported as P-value = 0.063. Find the error in the reasoning.     This is a right-tailed test so the P-value should be 0.9370.     This is a two-tailed test so the P-value should be 0.126.     The P-value should have been calculated using the studentâ s t-distribution.     There is no error in the reasoning.     None of these.

For this problem, carry at least four digits after the decimal in your calculations. Answers may vary slightly due to rounding.How hard is it to reach a businessperson by phone? Let p be the proportion of calls to businesspeople for which the caller reaches the person being called on the first try. (a) If you have no preliminary estimate for p, how many business phone calls should you include in a random sample to be 80% sure that the point estimate p̂ will be within a distance of 0.06 from p? (Round your answer up to the nearest whole number.)phone calls(b) A report states that businesspeople can be reached by a single phone call approximately 18% of the time. Using this (national) estimate for p, answer part (a). (Round your answer up to the nearest whole number.)phone calls

How many Biology students’ records need to be sampled to estimate the percentage who earn "A"s to within 4.5% with 98% confidence?

It is bleieved that the percent of convicted felons who have a history of juvenile deliquency is 70%.  Is there evidence to support the claim that the actual percentage is more than 70% if out of 200 convicted felons, we find that 154 have a history of juvenile deliquency?  Set the level of significance at a = 0.05

What percent of our campus is female? If no preliminary study is made to estimate, how large a sample is needed be 99% sure that the error will be no more than 0.03 from?

In a recent year, the Better Business Bureau settled 73% of complaints they received. You have been hired by the Bureau to investigate complaints this year involving computer stores. You plan to select a random sample of complaints to estimate the proportion of complaints the Bureau is able to settle. Assume the population proportion of complaints settled for the computer stores is 0.73, as mentioned above. Suppose your sample size is 113. DO NOT USE THE EXCEL FORMULA. CALCULATE BY HAND OR WITH A CALCULATOR. 1. What is the probability that the sample proportion will be within 4 percent of the population proportion?

The head of a computer science department is interested in estimating the proportion of students entering the department who will choose the new computer engineering option. A preliminary sample indicates that the proportion will be around 0.35. Therefore, what size sample should the department head take if she wants to be 95% confident that the estimate is within 0.10 of the true proportion?

For this problem, carry at least four digits after the decimal in your calculations. Answers may vary slightly due to rounding. Small Businesses is interested in the proportion of small businesses that declared Chapter 11 bankruptcy last year. Since there are so many small businesses, the National Council intends to estimate the proportion The National Council from a random sample. Let p be the proportion of small businesses that declared Chapter 11 bankruptcy last year. (a) If no preliminary sample is taken to estimate p, how large a sample is necessary to be 99% sure that a point estimate p will be within a distance of 0.09 from p? (Round your answer up to the nearest whole number.) small businesses (b) In a preliminary random sample of 30 small businesses, it was found that twelve had declared Chapter 11 bankruptcy. How many more small businesses should be included in the sample to be 99% sure that a point estimate p will be within a distance of 0.090 from p? (Round your answer up…