{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

HomeWork_6

# HomeWork_6 - 9 25 = x and a standard deviation 7 2 = s a...

This preview shows pages 1–2. Sign up to view the full content.

Home Work 6 1. A random sample of 64 = n observations is drawn from a population with a mean equal to 20 and standard deviation equal to 16. a. Give the mean and standard deviation of the (repeated) sampling distribution of X . b. Describe the shape of the sampling distribution of X . Does your answer depend on the sample size? Find the probability that c. X is less than 16 d. X is greater than 23 e. X is greater than 25 f. X falls between 16 and 22 g. X is less than 14. 2. According to Business Travel News (July 15, 2002), the average salary of a travel management professional is \$74,000. Assume that the standard deviation of s salaries is \$30,000. Consider a random sample of 50 travel management professionals and let X represent the mean salary for the sample. a. What are x μ and x σ ? b. Describe the shape of the sampling distribution of X c. Find ) 000 , 65 \$ ( X P d. Find ) 000 , 79 \$ 000 , 70 (\$ < < X P . 3. A random sample of 90 observations produced a mean

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: 9 . 25 = x and a standard deviation 7 . 2 = s . a. Find a 95% confidence interval for the population mean . b. Find a 90% confidence interval for . c. Find a 99% confidence interval for . 4. Periodically, the Hillsborough County (Florida) Water Department tests the drinking water of homeowners for contaminants such as lead and copper. The lead and copper levels in water specimens collected for a sample of 10 residents of the Crystal Lakes Manors subdivision are shown in the next table. Lead (µg/L) Copper (mg/L) 1.32 .508 .279 13.1 .320 .919 .904 .657 .221 3.0 .283 1.32 .475 4.09 .130 4.45 .220 .743 1 a. Construct an 99% confidence interval for the mean lead level in water specimens from Crystal Lakes Manors. b. Construct an 99% confidence interval for the mean copper level in water specimens from Crystal Lakes Manors. 2...
View Full Document

{[ snackBarMessage ]}