Solutions for 02402 exam 15. December 20111

counts the ones corresponding to the event in question. And for the latter one of eachhas to be chosen:( ) ( ) ( )2 3 41 1 1P 2 =) = 6 21(93Hence the correct answer is 5.Exercise VIIn a store chain with separate bakery departments it is required, that the breads in allthe chain’s bakery shops are reasonably homogeneous. For the weight of a given breadthe following requirements are specified:1% of the breads are allowed to weigh below 600 g.5% of the breads are allowed to weigh above 650 g.Data are assumed to follow a normal distributionQuestion VI.1 (13) The mean and standard deviation (µ, σ) to be used for the productionto meet these requirements are? First we find the relevant percentiles of thestandard normal (Z) distribution:P (Z < z 0.99 ) = 0.01 and P (Z > z 0.05 ) = 0.05Hence these values can be found from R as qnorm(0.01) and qnorm(0.95) or in Table3:z 0.99 = −2.326 and z 0.05 = 1.645We need to find the µ and the σ that will give the same probabilities in a non-standardnormal X, so we can use the basic standardization formula Z = X−µ twice and solveσ2 equations with two unknowns:−2.326 = x 0.99 − µand 1.645 = x 0.05 − µσσthat is:−2.326 = 600 − µ and 1.645 = 650 − µσσThe solutions is the one given as answer 5: µ = 629.3g and σ = 12.6gExercise VIIFour medical drugs with the same active ingredient are compared in terms of sideeffects. 200 persons participate in a study where the side effects for the individualperson is categorized as none / light / serious. The results of the investigation isshown in the table below:7