The president of Jones Bank asked his research team to determine the average waiting time for its customer. A study of 100 customers was conducted with the following results: mean = 19.8 standard deviation = 2.06 minutes
Prepare the 95% confidence interval for average waiting time...
mean = 19.8
standard deviation = 2.06 minutes
sample / n = 100
95% confidence interval = 1.96
standard error = 2.06/sqrt 100 = 2.06/10 = .206
19.8 +/- 19.96 (.206)
19.8 +/- 0.40376
19.39 less than or equal to u less than or equal to 20.20
Jones Bank can be 95% confident that the average waiting time for customers is between 19.39 and 20.20
Prepare the 95% confidence interval for average waiting time...
mean = 19.8
standard deviation = 2.06 minutes
sample / n = 100
95% confidence interval = 1.96
standard error = 2.06/sqrt 100 = 2.06/10 = .206
19.8 +/- 19.96 (.206)
19.8 +/- 0.40376
19.39 less than or equal to u less than or equal to 20.20
Jones Bank can be 95% confident that the average waiting time for customers is between 19.39 and 20.20