Florida State University has 14 statistics classes scheduled for its Summer 2013

Question

Florida State University has 14 statistics classes scheduled for its Summer 2013 term. One class has space available for 30 students, eight classes have space for 60 students, one class has space for 70 students, and four classes have space for 100 students. a. What is the average class size assuming each class is filled to capacity? b. Space is available for 980 students. Suppose that each class is filled to capacity and select a statistics student at random. Let the random variable X equal the size of the student's class. Define the PDF for X c. Find the mean of X. d. Find the standard deviation of X.

Explanation / Answer

1) Average Class size = [1*30+8*60+1*70+4*100]/ 14 = 70

2) X can take the discrete values with the probability

30 30/980

60 480/980

70 70/980

100 400/980

The table for mean and standard deviation

Mean of X = 76.12

Standard deviation = 20.68

Mid point Frequency Mid-Point * Frequency (Mid-point -Mean)^2 * Frequency 30 0.030612 0.918367347 65.12083 60 0.489796 29.3877551 127.3143 70 0.071429 5 2.677456 100 0.408163 40.81632653 232.7092 0 0 0 0 Sum 1 76.12244898 427.8217 Mean 76.12244898 Standard deviation = Sqrt(427.8217/1) 20.68385

Related Questions

Navigate

• Browse (All)
• Browse F
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.