A police officer believes red cars speed more often than any other color car. During his 25 shifts this month, he records the number of speeding tickets he writes to red and non-red cars. a. Determine whether the following statement is true or false.

1. The police officer is conducting an experiment.

b. All of the following variables could be confounding variables EXCEPT for which one?

a. time of day
b. color of car
c. location
d. the police officer

Step-by-step explanation:

a. Yes, the following statement is true. The police officer is gathering data by writing down all the speeding tickets and seperating them into two categories, red and non-red cars. He can later analyze this data and compare them to determine whether or not his hypothesis is true.

b. The color of the car is the only variable that would not be a confounding variable in this scenario. This would instead be the independent variable and does not in any way affect the dependent variable which would be the number of speeding tickets received.

The minimum sample size required is 3385.

Step-by-step explanation:

In a sample with a number n of people surveyed with a probability of a success of , and a confidence level of , we have the following confidence interval of proportions.

In which

z is the zscore that has a pvalue of .

The margin of error is:

98% confidence level

So , z is the value of Z that has a pvalue of , so .

To estimate the proportion within 0.02 and with 98% confidence, what is the minimum required sample size if the company currently has no idea about the

The minimum sample size required is n.

We find n when

We don't know the true proportion, so we use , which is when the largest minimum sample size will be needed.

Rounding up

The minimum sample size required is 3385.