ospital workers who are routinely involved administrative radioactive tracer to patients are subject to a radiation exposure emanating from skin of the patient. In an experiment to assess the amount of this radiation levels were measured at a distance of 50 cm from n=28 patients who had been injected with a radioactive tracer, and a sample mean of 5.145 and sample std. s= 0.7524 are obtained. Can we be 95% confident that the average radiation level at a 50 cm. distance from patient is no more than about 5.5?

PEF is a measure of patient's abiltity to expel air from lungs. PEF for children free of asthma is 306. investigator wants to know whether children with chronic bronchitis have restricted PEF. sample of 40 children with chronic bronchitis are studied, their mean PEF is 279, standard deviation 71. Is there stastical evidence of lower mean PEF in children with chronic bronchities? Run appropriate test at alpha = 0.05

Mobile homes are tightly constructed for energy conservation. This can lead to a buildup of indoor pollutants. The paper "A Survey of Nitrogen Dioxide Levels Inside Mobile Homes"† discussed various aspects of NO2 concentration in these structures. (a) For one sample of mobile homes in the Los Angeles area, the mean NO2 concentration in kitchens during the summer was 38.52 ppb, and the standard deviation was 11.16. Making no assumptions about the shape of the NO2 distribution, what can be said about the percentage of observations between 16.20 and 60.84? (Round the answer to the nearest whole number.) at least % (b) Inside what interval is it guaranteed that at least 89% of the concentration observations will lie for the distribution in part (a)? , (c) For a sample of mobile homes that were not in Los Angeles, the average kitchen NO2 concentration during the winter was 23.88 ppb, and the standard deviation was 16.00. Do these values suggest that the histogram of sample observations did…

Does the average Presbyterian donate less than the average Catholic in church on Sundays? The 58 randomly observed members of the Presbyterian church donated an average of $24 with a standard deviation of $15. The 42 randomly observed members of the Catholic church donated an average of $31 with a standard deviation of $7. What can be concluded at the αα = 0.10 level of significance?   For this study, we should use Select an answer t-test for the difference between two dependent population means z-test for a population proportion t-test for a population mean t-test for the difference between two independent population means z-test for the difference between two population proportions  The null and alternative hypotheses would be:        H0:H0:  Select an answer p1 μ1  Select an answer ≠ > = <  Select an answer p2 μ2  (please enter a decimal)     H1:H1:  Select an answer p1 μ1  Select an answer < = ≠ >  Select an answer p2 μ2  (Please enter a decimal) The test statistic ?…