Assume that when adults with smartphones are randomly​ selected, 46​% use them in meetings or classes. If 20 adult smartphone users are randomly​ selected, find the probability that exactly 15 of them use their smartphones in meetings or classes.

usagirl007A

usagirl007A

Answered question

2020-11-27

Assume that when adults with smartphones are randomly​ selected, 46​% use them in meetings or classes. If 20 adult smartphone users are randomly​ selected, find the probability that exactly 15 of them use their smartphones in meetings or classes.

Answer & Explanation

Corben Pittman

Corben Pittman

Skilled2020-11-28Added 83 answers

Given:
μ=9.12
δ=Standard deviation=0.05
The z-score the value decreased by the mean, divided by the standard deviation.

z=((xμ)/δ)=(99.12)/0.05=2.40

Determine the corresponding probability using the normal probability table in the appendix.

P(Z2.40)

is given in the row starting with 2.4 and in the column standard with 0.00 of the standard normal probability table in the appendix.

P(X<9)=P(Z<2.40)=0.0082=0.82

Thus about 0.82% of the 9-ounce bags of this brand of potato chips weight less than the advertised 9 ounces.

It is not likely to pose a problem for the company that produced these chips, because the probability is small (less then 5%) and this then indicates that the event is unusual to occur.

Do you have a similar question?

Recalculate according to your conditions!

New Questions in High school probability

Ask your question.
Get an expert answer.

Let our experts help you. Answer in as fast as 15 minutes.

Didn't find what you were looking for?