The distribution of the time it takes for different people to solve a certain crossword puzzle is strongly skewed to the right with a mean of 30 minutes and a standard deviation of 15 minutes. The distribution of z-scores for those times is a) Normally distributed with mean 30 and SD 15.
b) skewed to the right with mean 30 and SD 15.
c) Normally distributed with mean 0 and SD 1.
d) skewed to the right with mean 0 and SD 1.
e) skewed to the right, but the mean and standard deviation cannot be determined without more information.