Question

Suppose data collected by observers at randomly selected intersections across the country revealed that in a sample of 100 drivers, 40 were using their cell phone. a. Give a point estimate of p. the true driver cell phone use rate (that is, the true proportion of drivers who are using their cell phone while driving). b. Compute a 95% confidence interval for p. c. Give a practical interpretation of the interval, part b. a. A point estimate for p is . ) b. The 95% confidence interval for p is ( (Round to two decimal places as needed.) c. Interpret this interval O A. We are confident that 95% of the population use a cell phone while driving OB. We are 95% confident that the true proportion of drivers using cell phones is inside this interval. O C. There is a 95% percent chance that the true proportion of drivers who use cell phones is outside this interval. OD. We are confident that 95% of the population do not use a cell phone while driving,

Answer 1

The statistical software output for this problem is :

One sample proportion summary confidence interval: p: Proportion of successes Method: Standard-Wald 95% confidence interval results: Proportion Count Total Sample Prop. Std. Err. L. Limit U. Limit 40 100 0.4 0.048989795 0.30398177 0.49601823

Point estimate = 0.4

The 99% confidence interval is : (0.30 , 0.50)

Option B is correct