A-sset income across individuals has a mean of $500 with standard deviation $400. In a simple random sample of 30 individuals, what is the probability that the total amount of asset income will exceed $18,000?

Respuesta :

Answer:

The probability that the total amount of asset income will exceed $18,000 is 0.0853

Step-by-step explanation:

Given;

Individual mean, μ = $500

Individual standard deviation, S.D = $400

Sample number = 30

Raw score, X = $18,000

Mean for 30 individuals, μ  = 30($500) = $15,000

If S.D = $400, then Variance = (S.D)² = ($400)², for 30 individual = 30($400)²

= $4,800,000

S.D for 30 individual [tex]=\sqrt{4,800,000} =2,190.89[/tex]

Z- score [tex]= \frac{X-\mu}{S.D} = \frac{18,000-15,000}{2190.89}[/tex]

Z = 1.369

P (X > $18,000) = P (Z > 1.37)

P(Z=1.37) = 0.9147

P(Z>1.37) = 1 - 0.9147 = 0.0853

Therefore, the probability that the total amount of asset income will exceed $18,000 is 0.0853