'Confident Interval\r'

' wasteweir 2012 Assignment 5 (Total Points Possible: 15) Name: streamer ID: Instructions: Use this page as your baffle page, and attach your groupwork behind your work. Your assignment answers should be in complete and grammatic on the wholey correct sentences. 1. According to the field of study Center for Health Statistics (2004), 22. 4% of swelleds are smokers. A haphazard s adeninele of 300 adults is obtained. (a) Describe the ingest dispersal of phat, the try on proportion of adults who smoke. (b) In a random examine of 300 adults, what is the chance that at least 50 are smokers? c) Would it be droll if a random sample of 300 adults results in 18% or less being smokers? beg off your answer.2. A simple machine at K&A Tube & Manufacturing Company produces a certain copper tubing component in a refrigeration unit. The tubing components produced by the maker have a mean diameter of 0. 75 inch with a standard deviation of 0. 004 inch. The quality-control teste r takes a random sample of 30 components at a time each week and calculates the mean diameter of these components. If the mean is either less than 0. 748 inch or great than 0. 752 inch, the inspector come togethers that the machine needs an adjustment. a) Describe the take distribution of the sample mean diameter for a random sample of 30 such components. (b) What is the probability that, based on a random sample of 30 such components, the inspector will conclude that the machine needs an adjustment when, in fact, the machine is correctly calibrated?3. In a random sample of 678 adult males 20 to 34 eld of age, it was secured that 58 of them have hypertension (high furrow pressure). Source: The Centers for Disease Control. (a) Obtain a check work out for the proportion of adult males 20 to 34 long time of age who have hypertension. b) Construct a 95% trustfulness separation for the proportion of adult males 20 to 34 who have hypertension. be the pledge interval. You wish to conduct your bear study to determine the proportion of adult males 20 to 34 old age old who have hypertension. (c) What sample size of it would be needed for the estimate to be at bottom 3 percentage points (interval length is 0. 06) with 95% confidence if you design the point estimate obtained in part (a)? (d) What sample size would be needed for the estimate to be within 3 percentage points with 95% confidence if you don’t have a preliminary estimate ( use up phat=. )? 4. A random sample of 60 get married couples who have been married 7 years was asked the deem of children they have.The results of the survey are as follows: 0 0 0 3 3 3 1 3 2 2 3 1 3 2 4 0 3 3 3 1 0 2 3 3 1 4 2 3 1 3 3 5 0 2 3 0 4 4 2 2 3 2 2 2 2 3 4 3 2 2 1 4 3 2 4 2 1 2 3 2 The selective information is also in Excel format on Blackboard: FamilySizeData. xls. (a) Obtain a point estimate for the mean and standard deviation number of children of all(a) couples who have been married 7 years. (b) Wh at is the shape of the distribution of the sample mean? Why? c) Compute a 95% confidence interval for the mean number of children of all couples who have been married 7 years. Interpret this interval. (d) Compute a 99% confidence interval for the mean number of children of all couples who have been married 7 years. Interpret this interval. (e) You wish to conduct your own study to determine the mean number of children of all couples who have been married 7 years. What sample size would be needed for the estimate to be within 0. 25 (interval length is 0. 5) with 99% confidence if you use the point estimates obtained in part (a)?\r\n'