Question 309465
In a large university, 20% of the students are business majors. A random sample of 100 students is selected, and their majors are recorded.
---
a. compute the standard error of the proportion.
Ans: sqrt[pq/n] = sqrt[0.2*0.8/100]
------------------------------------------
b. what is the probability that the sample contains at least 12 business majors?
Ans: Binomial Problem with n = 100 ; p = 0.2 ; 12<= x <=100
Ans: 1-binomcdf(100,0.2,11) = 0.9874
------------------------------------------
c. what is the probability that the sample contains less than 15 business majors?
Ans: binomcdf(100,0.2,14) = 0.0804
------------------------------------------
d. what is the probability that the sample contains between 12 and 14 business majors?
Ans: binomcdf(100,0.2,14)-binomcdf(100,0.2,11) = 0.0679
==============================================================
Cheers,
Stan H.
=====================