6.81 the length of time between breakdowns of an es- sential piece of equipment is important in the decision of the use of auxiliary equipment. an engineer thinks that the best model for time between breakdowns of a generator is the exponential distribution with a mean of 15 days. (a) if the generator has just broken down, what is the probability that it will break down in the next 21 days? (b) what is the probability that the generator will op- erate for 30 days without a breakdown?

a) 75.34%

b) 13.53%

Step-by-step explanation:

First, let us consider the cumulative exponential distribution

Where

and m denotes the mean

Therefore, our cumulative distribution for this exercise is as it follows:  

a) According to the distribution, the first question can be calculated as it follows:

Hence, the probability that the piece will break down in the next 21 days is 75.34%

b) Now, take into account that we now need the probability complement for applying the cumulative distribution like this:

Therefore, we have that the probability that the generator will operate for 30 days without a breakdown is 13.53%

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:

i need more details sorry

step-by-step explanation: