Determining sample size using cofident

Assignment Help Basic Statistics

Reference no: EM1319092

Q1) Company that produces electronic components knows that standard deviation of lifetimes of those components is 100 hours. Company wishes to estimate mean lifetimes of components with the error that will not exceed 20 hours.

How large sample size must be taken to be

a) 95% confident;

b) 99% confident, in their estimates?

Q2) Mean and standard deviation of random sample of 90 rivet heads produced by a company are 1.8451 mm and 0.0015 mm respectively. Determine a 99% confidence interval for mean diameter of all rivet heads manufactured by company. Also determine a 95% confidence interval for standard deviation of diameter of all rivet heads manufactured by company. Give your answers correct to four decimal places.

Reference no: EM1319092

Questions Cloud

Developing a hypothetical table of data using a grid : Develop a hypothetical table of data using a grid of 3 rows and four columns.

Simplify the number : Simplify the number

Meaning of term contingencies : Illustrate out the meaning of the term contingencies. Should contingency costs be included in a project proposal? Explain your answer.

Use graph to solve question : Use graph to solve question

Determining sample size using cofident : How large sample size must be taken to be 95% confident.

Probability for the mean weight for a sample : What is the probability that the mean weight for a sample of 40 trout exceeds 405.5 grams?

Assume to two firms in an industry with an index : Assume to two firms in an industry with an index of 5,000 announce a merger. The U.S. Justice Department concludes the merger will boost the index to 5,500. The antitrust authorities will most likely.

Estimate of the average tread life : What is the best estimate of the average tread life for the entire population of these tires?

A goodness of fit test and test of independence : Last school year, student body of a local university consisted of 30% freshmen, 24% sophomores, 26% juniors, and 20% seniors. A sample of 300 students taken from this year's student body showed the following number of students in each classificati..

User Account

All Pages