Question

2. A 90% confidence interval for the mean percentage of airline reservations being canceled on the day of the flight is (1.1%, 3.2%). What is the point estimator of the sample mean of reservations that are canceled on the day of the flight?

1. 1.60%
2. 2.15%
3. 2.1%
4. 1.05%

3. A 90 % confidence interval for the mean percentage of airline reservations being canceled on the day of the flight is (1.1%, 3.2%). What is the margin of error of this confidence interval?

1. 1.60%
2. 2.15%
3. 2.1%
4. 1.05%

Answer 1

Solution :

2)   = (Lower confidence interval + Upper confidence interval ) / 2

Sample mean = = (1.1% + 3.2%) / 2

Sample mean = = 2.15%

correct option is = b

3) Margin of error = E = Upper confidence interval -   

Margin of error = E = 3.2% - 2.15%

Margin of error = E = 1.05%

correct option is = d