Answer:
Probability of getting all three correct answer = [tex]\frac{1}{64}[/tex]
Step-by-step explanation:
Given - A multiple choice test contains questions with four options each: A, B, C, or D. If Natalie randomly guesses on the last three questions.
To find - what is the probability that she gets all three correct.
Proof -
Given that, question has 4 options.
And 1 option can be correct,
Let
x be that Natalie gives correct answer.
So,
Probability of getting, correct answer, P(x) = [tex]\frac{1}{4}[/tex]
So,
Probability of getting, incorrect answer, P(x') = 1 - [tex]\frac{1}{4}[/tex] = [tex]\frac{3}{4}[/tex]
Now,
Given that, she guess the 3 questions.
All correct means,
first, second, third question answer is correct.
So,
Probability of getting all three correct answer = [tex]\frac{1}{4}[/tex]×[tex]\frac{1}{4}[/tex]×[tex]\frac{1}{4}[/tex] = [tex]\frac{1}{64}[/tex]