If standard deviation of x is 5, standard deviation of y = 2x–3 is 7.

The correlation coefficient between x and (a – x) is –1.

The mean and the standard deviation of a characteristic of 100 items were found to be 60 and 10 respectively. At the time of calculations, two items were wrongly taken as 5 and 45 instead of 30 and 20. Calculate the corrected mean and corrected standard deviation.

Investigate the association between darkness of eye-colour in father and son from the following data:

Fathers with dark eyes and sons with dark eyes: 50

Fathers with dark eyes and sons with not dark eyes: 79

Fathers with not dark eyes and sons with dark eyes: 89

Fathers with not dark eyes and sons with not dark eyes: 782

Also tabulate for comparison the frequencies that would have been observed had there been no heredity.

The following table gives, according to age, the frequency of marks obtained by 100 students in an intelligence test:

Compute coefficient of variation for factory A and B from the following:

The regression coefficients byx and bxy of a data are 1.2 and 0.8, respectively