Question

Can someone show me how to do this on excel?

Question involves cell phone users.

Mean monthly data usage = 5.8 GB/month

StDev monthly data usage = 2.5 GB/month

"Heavy users" are those that use >= 9 GB/month

a.) What is the probability a "heavy user" uses more than 10 GB/month?

b.) Two users are selected at random. What is the probability at least one of them is a heavy user?

c.) Five users are selected at random. What is the probability that at least one of them is a heavy user?

Again, I am looking for the EXCEL formula to solve these. THANK YOU!!!!

Answer 1

we have Given,

Mean monthly data usage = 5.8 GB/month

StDev monthly data usage = 2.5 GB/month

a.) What is the probability a "heavy user" uses more than 10 GB/month?

let x=heavy user

p(x>1)=?

mean	5.8
sd	2.5
probability of havey user	0.025263

b.) Two users are selected at random. What is the probability at least one of them is a heavy user?

probability at least one of them is a heavy user means 1- probability of none of them are heavy user.

probability at least one of them is a heavy user means

0.0755284

c.) Five users are selected at random. What is the probability that at least one of them is a heavy user?

users	probability
1	0.025263
2	0.050266
3	0.085228
4	0.123141
5	0.151612

for the code of probability in the excel please check the attached screenshot.

the code is" NORM.DIST(x,mean,standard_dev,cumulative)"

The NORM.DIST function syntax has the following arguments:

• X     Required. The value for which you want the distribution.

• Mean     Required. The arithmetic mean of the distribution.

• Standard_dev     Required. The standard deviation of the distribution.

• Cumulative     Required. A logical value that determines the form of the function. If cumulative is TRUE, NORM.DIST returns the cumulative distribution function; if FALSE, it returns the probability density function.