The amount of time part time worker at a pet store is normallydistributed with a mean of 25 hours and a standard deviation of 2.5hours. In a random sample of 25 employees, what is the probabilitythat a worker will work for between 24 and 26 hours?
A student goes to the university library. The probability thatthe student checks out the science book for the science class is0.40; the probability that the student checks out the math book is0.30; and the probability that the student checks out both thescience and math book is 0.20. What is the probability that thestudent checks out the science and the math book?
Dutch elm disease of American elm trees is caused by a fungus.It is known that 95% of elm trees in a city that have been treatedwith a fungicide recover from the disease. What is the probabilitythat in a random sample of 4 elm trees in this city, at least 3trees recover when treated with the fungicide?
A canning company claims that the amount of sugar in a cup ofcherries is 13.2 grams. The population is normally distributed witha population standard deviation known to be 0.5 grams. Theresearcher took a sample of 25 cups of cherries and found a mean of12.95 grams of sugar. Test at the 5% significance level that theamount of sugar in a cup of cherries is different than what thecompany claims. What is the p value for this test and what is yourconclusion?
