16. For a standard normal distribution, what is the probability that zis greater than 1.25? 17. What is the area under the normal curve between z= 0.0 and z = -1.35? 18. The mean amount spent by a family of four on food is $800 per month with a standard deviation of $75. Assuming that the food costs are normally distributed, what is the probability that a family spends less than $610 per month? 19. The mean score of a college entrance test is 700; the standard deviation is 50. The scores are normally distributed. What percent of the students scored below 620? I