Answers
From the data we can see that there are 26 students enrolled in 12 or more credits in a semester
Total number of students = 40
a) Let p = proportion of students from the respondents that are full-time students
p = 26/40 = 0.65 = 65%
Percent of respondents in the student dataset are “full-time” students = 65%
b) n = 20 sample class of 20 students
p = 0.65 best estimate for probability of randomly selected student being full-time
Let X be the number of students being full-time in the class of 20 students
X ~ Binomial distribution with n = 20 and p = 0.65
To find P(X=20)
We use the Excel function BINOM.DIST to find the probability
P(X=20) = BINOM.DIST(20,20,0.65,FALSE)
= 0.000181
P(in a class of 20 students they will all be full-time) = 0.000181