Question

It is advertised that the average braking distance for a small car traveling at 65 miles per hour equals 120 feet. A transportation researcher wants to determine if the statement made in the advertisement is false. She randomly test drives 34 small cars at 65 miles per hour and records the braking distance. The sample average braking distance is computed as 115 feet. Assume that the population standard deviation is 20 feet.

State the null and the alternative hypotheses for the test.

Answer 1

The answer is 120

Explanation:

Answer 2

`H_(\0):\mu =120`
`H_(\0):\mu \\eq 120`

Explanation:

it is given in question that

sample space n=34

μ the population mean =120

the sample mean
`\bar{x}=115`

the population standard deviation σ=20

we have to find the null hypothesis and alternative hypothesis

null hypothesis

the average braking distance for a small car travelling at 65 miles per hour equals to 120 feet

so
`H_(\0):\mu =120`

Alternative hypothesis

the average braking distance for a small car travelling at 65 miles per hour not equals to 120 feet

so
`H_(\0):\mu \\eq 120`