Question

The director of admissions at Kinzua University in Nova Scotia estimated the distribution of student admissions for the fall semester on the basis of past experience.

Admissions Probability

1,080 0.5

1,340 0.1

1,640 0.4

(1) What is the expected number of admissions for the fall semester? Expected number of admissions

(2) Compute the variance and the standard deviation of the number of admissions. (Round your standard deviation to 2 decimal places.) Variance Standard deviation

Answer 1

x	P(X=x)	xP(x)	x2P(x)
1080	0.500	540.00000	583200.00000
1340	0.100	134.00000	179560.00000
1640	0.400	656.00000	1075840.0000
total		1330.0000	1838600.0000
	E(x) =μ=	ΣxP(x) =	1330.0000
	E(x2) =	Σx2P(x) =	1838600.0000
	Var(x)=σ2 =	E(x2)-(E(x))2=	69700.0000
	std deviation=	σ= √σ2 =	264.01

1)

expected number =1330

2)

variance =69700

standard deviation =264.01