Question

n a certain stretch of West Street, I claim that most cars are going more than 5 miles per hour (mph) over the speed limit. The speed limit is posted at 25 mph. In a random sample of 70 cars, 46 of them were traveling faster than 30 mph. Test my claim at the 0.01 significance level. (a) What is the sample proportion of cars going more than 5 mph over the speed limit?

Answer 1

Answer: $\dfrac{23}{35}$

Step-by-step explanation:

Given : A certain stretch of West Street, I claim that most cars are going more than 5 miles per hour (mph) over the speed limit.

The speed limit is posted at 25 mph.

In a random sample of 70 cars, 46 of them were traveling faster than 30 mph (25+5).

Number of cars going more than 5 mph over the speed limit=46

Then,  the sample proportion of cars going more than 5 mph over the speed limit will be :_

$\dfrac{\text{Number of cars going more than 5 mph over the speed limit}}{\text{Sample size}}\\\\=\dfrac{46}{70}=\dfrac{23}{35}$

Hence, the sample proportion of cars going more than 5 mph over the speed limit = $\dfrac{23}{35}$