The scores on a college entrance exam have an approximate normal distribution with mean, =54 points and a standard deviation, =13 points.

Enter the exact answers in increasing order.

(a) About68% of the y values lie between______and_____ .The z-scores are___and____, respectively.

(b)About 95% of the y values lie between____and____.The z-scores are___and_____, respectively.

(c) About 99.7% of the y values lie between____and___.The z-scores are___and___ respectively.