A-Using either the table or Excel, nd the following probabilities: a) P(Z 1:25) c) P(Z

A-Using either the table or Excel, nd the following probabilities:

a) P(Z <=1.25)

b) P(Z > 1:25)

c) P(Z<=-1.25)

d) P(-0.38 <=Z <=1.25)

B- The breakdown voltage of a randomly chosen diode of a particular type is known to be normally dis-

tributed. What is the probability that a diodes breakdown voltage is within 1 standard deviation of its mean value? How about within 2 standard deviations of its mean value? (Please show all the necessary steps in your answer).

C- Suppose that 25% of all students at a large public university receive nancial aid. Let X be the number

of students in a random sample of size 50 who receive nancial aid. Find the following probabilities,

using appropriate approximations:

a) at most 10 students receive nancial aid

b) between 5 and 15 (both inclusive) students receive nancial aid

D- Let X denote the distance (in meters) that an animal moves from its birth site to the rst territorial vacancy it encounters. Suppose that for banner-tailed kangaroo rats, X has an exponential distribution with parameter = 72:46. Find the probability that the distance is:

a) at most 100 meters

b) at most 200 meters

c) between 100 and 200 meters