Question

FIU is interested in the popularity of its bookstore. A recent survey of students at Florida International University found that only 33% of its students buy their textbooks at FIU's bookstore. If randomly selected groups of 50 students are surveyed, what would the standard deviation be for the number of students, in groups of 50, who buy their textbooks from the university bookstore?

Answer 1

Standard deviation formula for this is given as

`\begin{gathered} \sigma=√(np(1-p)) \\ where\text{ }\sigma=standard\text{ deviation = ?} \\ p=probability=33\%=(33)/(100)=0.33 \\ n=sample\text{ size = 50} \end{gathered}`

Applying we have

`\begin{gathered} \sigma=√(50(0.33)(1-0.33)) \\ \sigma=√(50*0.33*0.67) \\ \sigma=√(11.055) \\ \sigma=3.324906 \end{gathered}`

Hence the answer is 3.325