A survey of Amazon. com shoppers reveals the following probability distribution of the number of books purchased per hit.

X 0 1 2 3 4 5 6 7

P(X) .35 .25 .20 .08 .06 .03 .02 .01

a. What is the probability that an Amazon. com visitor will buy four books?
b. What is the probability that an Amazon. com visitor will buy eight books?
c. What is the probability that an Amazon. com visitor will not buy any books?
d. What is the probability that an Amazon. com visitor will buy at least one book?

a)

b)

c)

d)

Step-by-step explanation:

For this case we define the random variable X as "number of books purchased per hit."

And as we can see the distribution for x is given by:

X       0     1    2     3    4     5    6    7

P(X) .35 .25 .20 .08 .06 .03 .02 .01

Part a

For this case we want this probability:

from the probability distribution given

Part b

For this case we want this probability:

from the probability distribution given since the value of X=8 is not in the distribution

Part c

For this case we want this probability:

from the probability distribution given

Part d

For this case we want this probability:

And we can use the complement rule like this:

this story was prepared by jim

mccullaugh in los angeles and

al stewart in new york.

new york the colossal success of "top gun" appears to have dramatically altered madison avenue's

perception of corporate sponsorship

of home video projects.

the paramount home video re- lease, featuring a 60- second diet

pepsi spot, was by no means the

first prerecorded video to carry an advertiser's plug, but it was the

first major theatrical release to do so. in the aftermath of the title's

success, paramount is widely ex- pected to ink a similar deal for

"crocodile dundee" or "star trek

iv" or both.

corporate america's new attraccds push british

recording sales

to 19% gain

london fueled by the compact

disk boom, the value of u.k. manu- facturer shipments of recordings

rose 19% in the 12 -month period ended march 1987, according to the

british phonographic industry.

total value of u.k. shipments for

the period was $755 million for all

configurations. (all value figures

are based on an exchange rate of

$1.68 to the pound sterling.)

cd sales totaled 10.7 million units

worth $121.3 million- compared

with 3.7 million units worth $39.5

million in the prior 12 months -and

accounted for two -thirds of the

overall gain in trade value. at present growth rates, says the bpi, cd

sales for calendar 1987 will reach 20

(continued on page 79)

step-by-step explanation:

the correct is answer is a 9-sided polygon!