Question

Need help with excerise step by step been 20 year's

Answer 1

Given:

Standard deviation

`\sigma=5.18`

Mean

`\mu=129`

Required:

Find the longest braking distance one of these cars could have and still in the bottom.

Step-by-step explanation:

The z-score formula is given as:

`z=(x-\mu)/(\sigma)`

Substitute the given values and find the value of z.

`z=(x-129)/(5.18)`

This is the first percentile which is X when Z has a p-value of 0.01, so z = -2.327.

`\begin{gathered} -2.327=(x-129)/(5.18) \\ x-129=-2.327(5.18) \\ x-129=-12.054 \\ x=129+12.054 \\ x=116.946\text{ ft} \end{gathered}`

Final answer:

The longest braking distance one of these cars could have and still in the bottom 1% is 116.946 ft.