Question

The sales department has determined that the average purchase value for their catalog business is normally distributed with a mean of $41.34 and a standard deviation of $13.54. What is the purchase value at the 30th percentile

Answer 1

The purchase value at the 30th percentile=34.24

Explanation:

We are given that

Mean,
`\mu=41.34`

Standard deviation,
`\sigma=13.54`

We have to find the purchase value at the 30th percentile.

`xth percentile =\mu+Z* \sigma`

Where Z is the critical value of x% confidence interval

x=30

Critical value of Z at 30% confidence interval=-0.5244

Using the formula

30th percentile=
`41.34+(-0.5244)(13.54)`

30th percentile=
`41.34-7.100376`

30th percentile
`\approx 34.24`

Hence, the purchase value at the 30th percentile=34.24