Answer:
0.31084
Step-by-step explanation:
When given a question where by a random sample is chosen for the population, the z score formula used =
z = (x-μ)/Standard error
where x is the raw score
μ is the population mean
Standard error = σ/√n,
σ is the population standard deviation
n = number of samples
For x = $114,000, μ = $115,000, σ = 25,000, n = 100
z = (x-μ)/Standard error
= z = (x-μ)/ σ/√n
z = 114,000 - 115,000/ 25,000/√100
= -1000/25,000/10
= -1000/2500
z = -0.4
Determining the probability value from Z-Table:
P(x = 114000) = P(z = -0.4)
= 0.34458
For x = $116,000, μ = $115,000, σ = 25,000, n = 100
z = (x-μ)/Standard error
= z = (x-μ)/ σ/√n
z = 116,000 - 115,000/ 25,000/√100
= 1000/25,000/10
= 1000/2500
= 0.4
Determining the Probability value from Z-Table:
P(x = 116000) = P(z = 0.4)
= 0.65542
The probability that the sample mean selling price was between $114,000 and $116,000 is calculated as
= P(114,000< x < 116,000)
= P(-Z<x<Z)
= P(-0.4<x< 0.4
= 0.65542 - 0.34458
= 0.31084
Therefore, the probability that the sample mean selling price was between $114,000 and $116,000 is 0.31084
(Note that -8 is not included)
. Note that the value of 4 is not included since it is opened.