Which of the following statements is true? . a) for joint variation, the product of the quantities is constant.. b) for direct variation, the ratio of the two quantities is constant.. c) for inverse variation, the ratio of the two quantities is constant.. d) for direct variation, the product of the two quantities is constant.

15 points ! ~ see if you know the answer to both you!

How to do this , and can some one explain

The annual snowfall in a town has a mean of 38 inches and a standard deviation of 10 inches. last year there were 63 inches of snow. find the number of standard deviations from the mean that is, rounded to two decimal places. 0.44 standard deviations below the mean 2.50 standard deviations below the mean 0.44 standard deviations above the mean 2.50 standard deviations above the mean