Answer:
The probability that she gets all 7 questions correct is 0.0078.
Step-by-step explanation:
We are given that Karri takes a 7 question true-false test and guess on every question.
The above situation can be represented through binomial distribution;
where, n = number of samples (trials) taken = 7 question
r = number of success = all 7 questions correct
p = probability of success which in our question is probability that
question is correct, i.e. p = 50%
Let X = <u><em>Number of question that are correct</em></u>
So, X ~ Binom(n = 7, p = 0.50)
Now, the probability that she gets all 7 questions correct is given by = P(X = 7)
P(X = 7) =
=
= <u>0.0078</u>