Find the 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

mean = np = .23(14) =3.22

variance = npq = 3.22(.77) =2.4794

standard deviation = sd = sqrnpq = sqr(2.4794) =1.5746

z score = 3-3.22)/1.5746 =-.139717

use either z tables or calculator to find Pr(x>3) which should be slightly larger than 50%

Pr(x>3)= .55556= 55.556% chance more than 3 students will attend Tet festivities