Find probability

Question

A school newspaper reporter decides to randomly survey 14 students to see if they will attend Tet festivities this year. Based on past years, she knows that 23% of students attend Tet festivities. We are interested in the number of students who will attend the festivities.

Find the probability that at most 4 students will attend. (Round your answer to four decimal places.)

Answer 1

Expected Value = np = 14(0.23) = 3.22

Standard Deviation = √(npq) = √[14(0.23)(0.77)] ≈ 1.5746

Z-score = (x-µ)/σ = (4-3.22)/1.5746 ≈ 0.5

P(Z≤0.50) ≈ 0.6915

Therefore, the probability that 4 students at most will attend the Tet festivities is about 0.6915

Hope this helped!