I'm currently learning Bernoulli and Random Variables. I have tried this problem countless times and I can't seem to get it right. Anything can help! Thank you!
The probability that a randomly selected teenager watched a rented video at least once during a week was 0.74. What is the probability that at least 8 teenagers in a group of 10 watched a rented movie at least once last week? (Round your answer to four decimal places.)
P(X ≥ 8) =
Binomial Probability Formula/Bernoulli Theorem: nCr pr q(n - r), where:
n = number of trials (10 in this case)
r = number of successes (8, 9, 10 in this case, since @ least 8 signifies such)
P = probability of success (.74 in this case)
q = probability of failure, or 1 - n (1 - .74, or .26, in this case)
Calculating 8 successes should result in a probability of: 0.274
Calculating 9 successes should result in a probability of: 0.173
Calculating 10 successes should result in a probability of: 0.049
Calculating the probability that @ least 8 of 10 watched a rented movie = 0.274 + 0.173 + .049, or
In MS Excel, you can do: 1 - BINOMDIST(7,10,.74,1). You should get the above probability
On a TI-83/84, you can enter: 1 - BINOMCDF(10,0.74,7). You should get the above probability