1-The time for a human pregnancy is distributedN(39,1.46²)

weeks in the US.

a) A preterm baby is defined as a baby born earlier than37weeks. What percentage of babies are preterm?

Use 4 decimals.

b) A postmature baby is born after more than42weeks. What percentage of babies are postmature?

Use 4 decimals.

c) What percentage are neither preterm nor postmature?

Use 4 decimals.

d) My wife says those women who have the longest2% of pregnancies must be pretty miserable. How long do their pregnancies last?

Use 2 decimals.

weeks.

e) My first son was born early. In fact only35% of babies are born earlier than he was. How many weeks was it before he was born?

Use 2 decimals.

weeks.

2-The number of students who show up to the Laramie High School Prom is N(287,1296).

a) The Prom's capacity is407students. What is the probability the capacity will be broken this year?

Use 4 decimals

b) The planning committee worries this year will have the worst attendance in a decade. What number of students would mark the lowest5%?

Use 1 decimal place

students.

c) If more than half the students in the school show up - that's568students, the caterers will lose money. What is the probability this could happen?

Use 4 decimal places.

d) The distribution for the Natrona High School Prom in Casper is N(308,3249). If Laramie High School had390students show up, how many students would need to be at the Casper prom to have the same level of success?

Use 2 decimal places.

students.

3-When I was 16 I drove a Dodge Colt. The broken gas gauge always read empty, but I knew the distance it could go on a tank of gas is normally distributed with a mean of330miles and a standard deviation of19miles.

a) What is the probability that the next tank will go for exactly282miles?

Use 4 decimal places

b) What is the probability that the next tank will go for less than312.9miles?

Use 4 decimal places

There's no way to guarantee I'll never run out of gas, but I want to make sure it only happens3% of the time. How many miles do I dare drive before filling up again?

Use 1 decimal place

miles.