Suppose that we have found that in Jill's remote log-ins to a certain computer

1. Suppose that we have found that in Jill's remote log-ins to a certain computer, the number X of disk sectors she reads or writes has an approximate normal distribution with a mean of 500 and standard deviation of 15. Say we've set our network intrusion monitor to notify us every time Jill logs in and accesses 535 or more disk sectors. In what proportion of all such notifications will Jill have accessed at least 545 sectors?

2. Consider a certain river, and L, its level (in feet) relative to its average. There is a flood whenever L> 8, and it is reported that 2.5% of days have flooding. Let's assume that the level L is normally distributed: the above information implies that the mean is 0. Suppose the standard deviation of L,o,goes up by 10%. How much will the percentage of flooding days increase?