Question

1. USDOT wants to know if drivers are driving faster than the posted speed limit of 65 miles per hour. The speeds of a sample of randomly selected drivers are compared to 65 mph limit. The appropriate test to see if drivers are exceeding 65 would be a:

	a.	One sample t-test.
	b.	Independent samples t-test.
	c.	Matched (or dependent) paired samples t-test.
	d.	A one-way chi-square.

Answer 1

Here we will use one sample t test since here we want to test that whether mean speed is over 65 miles per hour or not based on the sample drawn from the population.

In order to conduct the test then hypothesis will be :

And since here population standard deviation is not known so we will use one sample t test and here test statistic will follow t distribution with n-1 degree of freedoms

So option A is correct.