# statistics

posted by .

) 43% of adults receive phone calls during the day. Amongst 10 randomly
selected people find the probability that
a. Adults receive exactly 4 phone calls.
b. Adults receive 8 or more phone calls.

• statistics -

Binomial distribution:
p=0.43 (probability of success)
q=1-p=0.57
N=10 (sample size)

Probability of r successes out of N:
P(X=r)=C(N,r)p^r*q^(N-r)
and C=combination=N!/(r!(N-r)!)
a. r=4
P(X=4)=C(10,4)*0.43^4*0.57^(10-4)=0.24

b. r≥8
P(X≥8)
=P(X=8)+P(X=9)+P(x=10)
= similar calculations as above

## Respond to this Question

 First Name School Subject Your Answer

## Similar Questions

1. ### Algebra

ABC phone company charges \$18 per month plus 7 cents per minute of phone calls. XYZ phone company charges \$9 per month and 10 cents per minute of phone calls. How many minutes of phone calls should be made each month to make the costs …
2. ### Smartphone Help

This is an assignment in which I have to list down Requirements, advantages, and disadvantages of a smartphone. These are the requirements needed. -send and receive phone calls -send and receive texts -on screen keyboard or physical …
3. ### statistics

A sales firm receives an average of four calls per hour on its toll-free number. For any given hour, find the probability that it will receive exactly eight calls
4. ### Math

On July 5th six different people reported to the police that they had seen Bigfoot, the large hairy creature sometimes seen but never captured. The next day, twice as many people called the police; sure they had seen the creature. …
5. ### Statistics

A local fire station receives an average of 0.5 rescue calls per day. Find the probability that on a randomly selected day, the fire station will receive fewer than two calls. (Round your answer to the nearest thousandth.)
6. ### Statistics

A local fire station receives an average of 0.5 rescue calls per day. Find the probability that on a randomly selected day, the fire station will receive fewer than two calls.
7. ### Math statistics

A mountain search and rescue team received an average of 600 calls per year. Use the poisson dustribution to find the probability that on a randomly selected day, they will receive 1 or more calls.
8. ### Math problem soving

Ok if someone can help me understand I greatly appreciated. I want to know how this is the answer. I got it wrong in my exam. The teacher explained it to me but I still don't get it. On July 5,in the area around center village,there …
9. ### Math problem soving

Ok if someone can help me understand I greatly appreciated. I want to know how this is the answer the numbers in table I know answer is day 6 but the pattern?
10. ### English

1. The cell phone vibrates when somebody calls me. 2. The cell phone vibrates when someone calls me at the phone. 3. The cell phone vibrates when a text message comes/arrives. 4. The cell phone vibrates when a text message is sent …

More Similar Questions