Case Seminar

Set 1 1. A genetics law says that children having one parent of blood group M and the other parent of blood group N will always be one if the three blood groups M, MN, N and that the average number of children in these groups will be in the ratio 1 : 2 : 1. The report on an experiment states as follows: “Of 162 children having one M parent, and one N parent, 28.4% were found to be of group M, 42% of group MN and the rest of the group N.” Do the data in the report conform to the expected genetic ratio 1 : 2 : 1? 2. The following table gives the count of yeast cells in square if a cyclometer. A square millimeter is divided into 400 equal squares and the number of these squares containing 0, 1, 2, … cells are recorded: No. of Cells | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | Frequency | 0 | 20 | 43 | 53 | 86 | 70 | 54 | 37 | 18 | 10 | 5 | 2 | 2 | 0 | 0 | 0 | 0 | Fit a Poisson distribution to the data and test the goodness of fit.
3. A drug manufacturer has installed a machine which automatically fills 5 gm of drug in each phial. A random sample of fills was taken and it was found to contain 5.02 gm on an average in a phial. The standard deviation of the sample was 0.002 gms. Test at 5% level of significance if the adjustment in the machine is in order. (Ans. tcal = 33.33, H0 is rejected.)
4. The heights of 10 males of a given locality are found to be 70, 67, 62, 68,61, 68, 70, 64, 64, 66 inches. Is it reasonable to believe that the average height is greater than 64 inches? Test at 5% significance level, assuming that for 9 degrees of freedom P(t > 1.83) = 0.05.
5. Eleven sales executive trainees are assigned selling jobs right after their recruitment. After a fortnight they are withdrawn from their field duties and given a month’s training for executive sales. Sales executed by them in thousands of rupees before and after the training, in the