It is advertised that the average braking distance for a small car traveling at 65 miles per hour equals 122 feet. A transportation researcher wants to determine if the statement made in the advertisement is false. She randomly test drives 38 small cars at 65 miles per hour and records the braking distance. The sample average braking distance is computed as 116 feet. Assume that the population standard deviation is 21 feet. (You may find it useful to reference the appropriate table: z table or t table) a. State the null and the alternative hypotheses for the test.

Complete Question

The complete question is shown on the first uploaded image

the null hypothesis is  

the alternative hypothesis is

The test statistics is  

The p-value is  

so

Step-by-step explanation:

From the question we are told that

   The population mean is  

     The sample size is  n=  38

    The sample mean is  

     The standard deviation is

Generally the null hypothesis is  

                the alternative hypothesis is

Generally the test statistics is mathematically evaluated as

substituting values

The p-value is mathematically represented as

From the z- table  

So  

part a

x     y

0     8

1     7.5

2     7

3     6.5

4     6

5     5.5  

for every hour i deducted .5 inches from the length of the candle

part b

it is a function because for every x value there is only one y value

part   c

for every x value there is only one y value

x       y

0       8

1       7.6

2       7.2

3       6.8

step-by-step explanation:

the answer is b