Probability four decimal places

Question

assume that when adults with smartphones are randomly selected 49% use them in meetings or classes if 8 adult smartphone users are randomly.selected find the probability that exactly 6 of them use their Smartphones in meetings or classes

Answer 1

This is a binomial distribution problem. The formula is:

P(r) = ⁿC^r · p^r (1 − p)^n−r.

where P(r) is the probability of exactly r successes out of n attempts, with p= the probability of a single success.

( ⁿC^r is the number of combinations of n items taken r at a time.)

In our case, r=6, n=8, and p=0.49.

So,

P(x) = [8!/(6!×2!)] × (0.49)⁶ × (1 - 0.49)^8-6

= (8*7/2) × (0.49)⁶ × (0.51)²

= 0.1008 to four decimal places of accuracy.