USE EXCEL SPREADSHEET TO ANSWER QUESTIONS Use Part-1 sheet to answer this questi

Question

USE EXCEL SPREADSHEET TO ANSWER QUESTIONS

Use Part-1 sheet to answer this question. Round your answers to 4 decimal places for a, b, c, and e. Put a box around your answers.

In a given hour, 30 individuals enter a certain store. Past experience indicates that 30% of all individuals entering the store decide to make a purchase. Based on the relevant binomial distribution, answer the following questions about X, the number of customers entering the store will make a purchase:

a)      What is the probability X is exactly 3?

b)      What is the probability that X is no more than 10?

c)      What is the probability that X is at least 15?

d)     Determine the mean and standard deviation of X.

e)      What is the probability that X will be within two standard deviations of the mean?

Use Part-2 sheet to answer this question. Round your answers to 4 decimal places. Put a box around your answers.

Suppose that X, the number of customers arriving each hour at the only checkout counter in a local pharmacy, is approximately Poisson distributed with an expected arrival rate of 20 customers per hour.

a)      Find the probability that X is exactly 10.

b)      Find the probability that X is at least 5.

c)      Find the probability that X is no more than 25.

d)     Find the probability that X is between 10 and 30 (inclusive).

Explanation / Answer

1)

a) probability X is exactly 3 =binomdist(3,30,0.30,false)=0.0072

b)probability that X is no more than 10 =P(X<=10)=binomdist(10,30,0.30,true) =0.7304

c)  probability that X is at least 15=P(X>=15) =1-P(X<=14) =1-binomdist(14,30,0.30,true)=0.0169

d) mean =np =30*0.3 =9

and std deviation =(np(1-p))1/2 =2.51

e) P(9-2*2.51<X<9+2*2.51)=P(4<=X<=14)=binomdist(14,30,0.30,true)-binomdist(3,30,0.30,true) =0.9737

2)

a)probability that X is exactly 10 =poisson(10,20,false)=0.0058

b) probability that X is at least 5=P(X<=5) =1-P(X<=4)=1-poisson(4,20,true) =1.0000

c)probability that X is no more than 25=P(X<=25) =poisson(25,20,true) =0.8878

d) probability that X is between 10 and 30=P(10<=X<=30)=poisson(30,20,true)-poisson(9,20,true)=0.9815

Related Questions

Navigate

• Browse (All)
• Browse U
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.