In: Statistics and Probability
Insurance companies are interested in knowing the population percent of drivers who always buckle up before riding in a car. They randomly survey 382 drivers and find that 283 claim to always buckle up. Construct a 85% confidence interval for the population proportion that claim to always buckle up. Use interval notation, for example, [1,5]
With the given information in the question we have to calculate the 85% confidence interval for the population proportion that always buckle up.
Sample proportion,
is the sample proportion for the drivers who always buckle up before driving.
Confidence interval formula for population proportion:
For 85% confidence interval,
So, the 85% confidence interval for the population proportion of drivers who always buckle up before riding in a car is .
Hence, we can say that we are 85% confident that the population proportion of drivers who buckle up before riding in a car is in between interval