help please

[-I1 Points] MENDSTATC4 8.E.081 . ASK YOUR TEACHER PRACTICE ANOTHER A random sampling of a company's monthly operating expenses for n = 81 months produced a sample mean of $5,265 and a standard deviation of $765. Find a 90% upper condence bound for the company's mean monthly expenses. (Round your answer to two decimal places.) $ You may need to use the appropriate appendix table or technology to answer this question. Need Help? "\" [-I1 Points] MENDSTATC4 8.E.084. ASK YOUR TEACHER PRACTICE ANOTHER Canadians are becoming more conscious of the importance of good nutrition, and some researchers believe that we may be altering our diets to include less red meat and more fruits and vegetables. To test this theory, a researcher decides to select hospital nutritional records for subjects surveyed 10 years ago and to compare the average amount of beef consumed per year to the amounts consumed by an equal number of subjects she will interview this year. She knows that the amount of beef consumed annually by Canadians ranges from 0 to approximately 49 kg. How many subjects should the researcher select for each group if she wishes to estimate the difference in the average annual per-capita beef consumption correct to within 2.4 kg with 99% condence? (Round your answer up to the nearest whole number.) subjects Need Help? {-11 Points] MENDSTATC4 8.E.088. ASK YOUR TEACHER PRACTICE ANOTHER Suppose you wish to estimate the difference between the mean acidity for rainfalls at two different locations, one in a relatively unpolluted area and the other in an area subject to heavy air . pollution. If you wish your estimate to be correct to the nearest 0.1 pH, with probability near 0.90, approximately how many rainfalls (pH values) would have to be included in each sample? (Assume that the variance of the pH measurements is approximately 0.3 at both locations and that the samples will be of equal size. Round your answer up to the nearest whole number.) n1 = n2 = rainfalls You may need to use the appropriate appendix table or technology to answer this question. Need Help? E [-11 Points] MENDSTATC4 8.E.075. ASK YOUR TEACHER PRACTICE ANOTHER Independent random samples of size 80 are drawn from two quantitative populations, producing the sample information in the table. Sample 1 Sample 2 Sample Size 80 80 Sample Mean 15 9 Sample Standard Deviation 5 6 Find a 95% upper condence bound for the difference in the two population means (,41 \"2). (Round your answer to two decimal places.) You may need to use the appropriate appendix table or technology to answer this question. Need Help? _'' [-11 Points] MENDSTATC4 8.E.078.S. - ASK YOUR TEACHER PRACTICE ANOTHER Independent random samples of n1 = n2 = n observations are to be selected from each of two populations 1 and 2. If you wish to estimate the difference between the two population means correct to within 0.16, with probability equal to 0.90, how large should n1 and n2 be? Assume that you know 0'12 z 522 r 28.4. (Round your answer up to the nearest whole number.) m use SA 1 = n2 = observations You may need to use the appropriate appendix table to answer this question. Need Help? n Last year's records of auto accidents occurring on a given section of highway were classied according to whether the resulting damage was $1,000 or more and to whether a physical injury resulted from the accident. The data follows. Under $1,000 $1,000 or More Number of Accidents 35 41 Number Involvlng Injurles 9 24 (a) Estimate the true proportion of accidents involving injuries when the damage was $1,000 or more for similar sections of highway. (Round your answer to three decimal places.) Find the 95% margin of error. (Round your answer to three decimal places.) (b) Estimate the true difference in the proportion of accidents involving injuries for accidents with damage under $1,000 and those with damage of $1,000 or more. Use a 95% condence interval. (Use p1 p2 where p1 is the proportion of accidents involving injuries with damage under $1,000 and p2 is the proportion of accidents involving injuries with damage of $1,000 or more. Round your answers to three decimal places.) to You may need to use the appropriate appendix table or technology to answer this question. Need Help? f [-l2 Points] MENDSTATC4 8.E.073. ASK YOUR TEACHER PRACTICE ANOTHER Find a 90% one-sided upper condence bound for the population mean 14 for these values. (Round your answers to two decimal places.) (a) n=33, 52:66, =so (b) n = 100, s = 2.4, x = 1.9 You may need to use the appropriate appendix table or technology to answer this question. Need Help? f