# Question: A small town contains a total of 1 800 households The

A small town contains a total of 1,800 households. The town is divided into three districts, containing 820, 540, and 440 households, respectively. A stratified random sample of 300 households contains 120, 90, and 90 households, respectively, from these three districts. Sample members were asked to estimate their total energy bills for the winter months. The respective sample means were $290, $352, and $427, and the respective sample standard deviations were $47, $61, and $93.

a. Use an unbiased estimation procedure to estimate the mean winter energy bill for all households in this town.

b. Use an unbiased estimation procedure to find an estimate of the variance of the estimator of part a.

c. Find a 95% confidence interval for the population mean winter energy bill for households in this town.

a. Use an unbiased estimation procedure to estimate the mean winter energy bill for all households in this town.

b. Use an unbiased estimation procedure to find an estimate of the variance of the estimator of part a.

c. Find a 95% confidence interval for the population mean winter energy bill for households in this town.

## Answer to relevant Questions

Refer to Exercise 17.2. If a total sample of 130 faculty members is to be taken, determine how many of these should be full professors under each of the following schemes. a. Proportional allocation b. Optimum allocation, ...An auditor wants to estimate the mean value of a corporation's accounts receivable. The population is divided into four strata, containing 500, 400, 300, and 200 accounts, respectively. On the basis of past experience, it is ...A city is divided into 50 geographic subdivisions. An estimate was required of the proportion of households in the city interested in a new lawn-care service. A random sample of three subdivisions contained 611, 521, and 734 ...In the analysis of Exercise 17.28, it was found that 9 of the sampled technical pages and 15 of the sampled nontechnical pages contained no errors. Find a 90% confidence interval for the proportion of all pages in this book ...Of the 1,395 colleges in the United States, 364 have 2-year schools. In a random sample of 40 two-year schools, it was found that the text Statistics Can Be Fun was used in 10 of the schools. In an independent random sample ...Post your question