SOLUTION: Assume that 17% of people are left-handed. If we select 5 people at random, find the probability of each outcome described below, rounded to four decimal places: a. There are some

Algebra ->  Probability-and-statistics -> SOLUTION: Assume that 17% of people are left-handed. If we select 5 people at random, find the probability of each outcome described below, rounded to four decimal places: a. There are some      Log On


   



Question 1152881: Assume that 17% of people are left-handed. If we select 5 people at random, find the probability of each outcome described below, rounded to four decimal places:
a. There are some lefties (≥1) among the 5 people.
b. There are exactly 3 lefties in the group.
c. There are at least 4 lefties in the group.
d. There are no more than 2 lefties in the group.
e. How many lefties do you expect?
f. With what standard deviation?

Answer by ikleyn(52781) About Me  (Show Source):
You can put this solution on YOUR website!
.

            It is a binomial distribution type problem.

            I will use a Technology to solve it quickly.

            I will use the Excel standard function BINOM.DIST to facilitate calculations.
            It has the analogue --- the standard function binompdf in pocket calculators TI-83 and TI-84.


(a)  P = sum%28C%285%2Ck%29%2A0.2%5Ek%2A%281-0.2%29%5E%285-k%29%2Ck=1%2C5%29 = 1 - C%285%2C0%29%2A0.2%5E0%2A%281-0.2%29%5E5 = 1 - BINOM.DIST(0,5,0.2,FALSE) = 0.67232.



(b)  P = C%285%2C3%29%2A0.2%5E3%2A%281-0.2%29%5E2 = BINOM.DIST(3,5,0.2,FALSE) = 0.0512.



(c)  P = sum%28C%285%2Ck%29%2A0.2%5Ek%2A%281-0.2%29%5E%285-k%29%2Ck=4%2C5%29 = 1 - sum%28C%285%2C0%29%2A0.2%5Ek%2A%281-0.2%29%5E%285-k%29%29 = 1 - BINOM.DIST(3,5,0.2,TRUE) = 0.00672.



(d)  P = sum%28C%285%2Ck%29%2A0.2%5Ek%2A%281-0.2%29%5E%285-k%29%2Ck=0%2C2%29 = BINOM.DIST(2,5,0.2,TRUE) = 0.94208.

On Excel function BINOM.DIST, see its description everywhere, for example
https://support.office.com/en-us/article/binom-dist-function-c5ae37b6-f39c-4be2-94c2-509a1480770c


On binompdf function for pocket calculators TI-83 and TI-84 see the link
http://users.rowan.edu/~schultzl/ti/binomial.pdf

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If you want to learn in more details on how to use this Technology, look into the lessons
    - How to calculate Binomial probabilities using Technology
    - Solving problems on Binomial distribution with Technology
in this site.

Look also into this links to the recently solved problem

https://www.algebra.com/algebra/homework/Probability-and-statistics/Probability-and-statistics.faq.question.1152847.html

https://www.algebra.com/algebra/homework/Probability-and-statistics/Probability-and-statistics.faq.question.1152847.html