Question;AP Stats Review Unit 8;1) An;agricultural field trial compares the yield of two varieties of tomato for;commercial use. The researchers divide in half each of 10 small plots of land;in different locations and plant each tomato variety on one half of each plot.;After harvest, they compare the yields in pounds per plant at each location.;The 10 differences (Variety A ? Variety B) give x-bar= 0.34 and a;sample standard deviation of s = 0.83. Is there convincing evidence of a;difference in yield at the 5% significance level? Describe what a Type I and;Type II error would be in this situation.;2) Popular wisdom is that eating;presweetened cereal tends to increase the number of dental cavities in;children. A sample of children was entered into a study (with parental consent);and was followed for several years. Each child was classified as a;sweetened-cereal lover or a nonsweetened-cereal lover. At the end of the study;the amount of tooth damage was measured by the number of cavities. The table;shows the mean number of cavities and the standard deviation for each group.;Group n;mean std. dev;Sugar 30;6.41 1.72;No sugar 35 5.20;2.34;Use a 90%;confidence interval to estimate the difference in the mean number of cavities;for children who eat sweetened cereal and children who don?t.;Does the sample provide evidence;that the mean number of cavities for children who eat sweetened cereal is more;than the mean number of cavities for children who do not eat sweetened cereal?;3) A study of chromosome abnormalities and;criminality examined data from 4,134 males born in Copenhagen. Each man was;classified as having a criminal record or not, using the registers maintained;in the local police offices. Each was also classified as having the normal male;XY chromosome pair or one of the abnormalities XYY or XXY. Of the 4,096 men;with normal chromosomes 381 had criminal records, while 11 of the 38 men with;normal chromosomes had criminal records. Some experts believe chromosome;abnormalities are associated with increased criminality. Do these data lend;support to this belief? Perform a significance test to answer this question.;Construct and interpret a 95%;confidence interval for the difference in proportions.
Paper#61937 | Written in 18-Jul-2015Price : $22