Question

The average price of a college math textbook is $179 and the standard deviation is $25. Suppose that 10 textbooks are randomly chosen. Round all answers to 4 decimal places where possible.

Answer 1

`α²ₓ=7.9056`

Explanation:

The average price of a college math textbook = $179

the standard deviation given= $25

Supposed number of textbooks =10

∴
`n=10`

mean value= 179

μ=161

`αₓ=α/√n`

`α²ₓ=7.9056`

Answer 2

σₓ² = 7.9056

Explanation:

Recall from the example given,

The average price of a math textbook =$179

The standard deviation =$25

The mean= 179

Standard deviation = 25

n =number of textbook randomly chosen which is 10

n=10

Then

Mean µ = 161

σ = 25

σₓ = σₓ/√n

= 25/√10

Therefore. σₓ² = 7.9056