Question

You have a 5 question multiple choice test. Each question has 4 choices. You don't know any of the answers. What is the experimental probability that you will guess exactly three out of five questions correctly

Answer 1

We're going to find the probability using Bernoulli trial's formulas: $P(x=3)= _{5}C_{3}\cdot (\frac{1}{4})^3\cdot (\frac{3}{4})^2=0.0879$.

Answer 2

You can calculate the theoretical probability, but to find out the experimental probability, you need to actually do it. Take the test a bunch of times. Find out how may times you got exactly 3 correct answers, and divide by the number of times you took the test.