a laptop manufacturer finds that the average time it takes an employee to load a laptop with software is 20 minutes with a standard deviation 8 minutes. suppose you take a random sample of 81 employees. the standard deviation of the sample mean is?
8/sqrt(81)=8/9=0.89
To calculate the standard deviation of the sample mean, also known as the standard error, you can use the formula:
Standard Error = Standard Deviation / √(Sample Size)
In this case, the standard deviation of the population is given as 8 minutes, and the sample size is 81 employees.
So, plugging in the numbers:
Standard Error = 8 minutes / √(81)
To find the square root of 81, you can calculate:
√(81) = 9
Now, substituting this value back into the formula:
Standard Error = 8 minutes / 9
The standard error of the sample mean for the given data is approximately 0.89 minutes.