Astudy of recent records of car accidents revealed that average proportion of drivers who were distracted by their phones at the time of accident was 35% with a margin error of 9%. if we want a margin of error of 4%, how many records needs to be studied? (all data analysis is done at the 95% confidence level).

At least 547 records need to be studied.

Step-by-step explanation:

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

In which

Z is the zscore that has a pvalue of .

And the margin of error is:

95% confidence interval

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

In this problem, we have that:

At least 547 records need to be studied.

answer: ask

step-by-step explanation: