STATISTICAL TECHNIQUES AND TOOLS
CONFIDENCE INTERVALS
|
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
|
A 90% confidence interval for the average salary of all CEOs in the electronics industry was constructed using the results of a random survey of 45 CEOs. The interval was ($139, 048, $154, 144). Give a practical interpretation of the interval.
|
|
90% of the sampled CEOs have salaries that fell in the interval $139, 048 to $154, 144
|
|
|
We are 90% confident that the mean salary of all CEOs in the electronics industry falls in the interval $139, 048 to $154, 144.
|
|
|
90% of all CEOs in the electronics industry have salaries that fall between $139, 048 to $154, 144
|
|
|
We are 90% confident that the mean salary of the sampled CEOs falls in the interval $139, 048 to $154, 144.
|
Explanation:
Detailed explanation-1: -The critical t value for a 90% confidence interval and a sample size, n, equal to 10, can be calculated using the excel formula shown below. The degree of freedom df is calculated as df = n-1= 10-1=0, and the confidence level is c = 0.90, and the significance level is = 1-c = 1-0.90 = 0.10.
Detailed explanation-2: -A 90% confidence level means that we would expect 90% of the interval estimates to include the population parameter; a 95% confidence level means that 95% of the intervals would include the parameter; and so on.
There is 1 question to complete.