Two days before a skiing competition, the depths of snow, x metres, at 32 points on the course were measured and it was discovered that the numerical values of Σx and Σx² were equal.

a. Given that the mean depth of snow was 0.885m, find the standard deviation of x.

b. Snow fell the day before the competition, increasing the depth over the whole course by 1.5cm. Explain what effect this had on the mean and on the standard deviation of x.