12) Suppose you know that the standard deviation of a variable is 10, and you have 100 observations, the standard deviation of the mean is

To find the standard deviation of the mean, also known as the standard error, you can follow these steps:

1. Calculate the standard deviation of the population (given as 10) and the number of observations (given as 100).

2. Divide the standard deviation of the population by the square root of the number of observations.

In this case, the standard deviation of the mean can be calculated as follows:

Standard Deviation of the Mean = Standard Deviation of the Population / √Number of Observations

Standard Deviation of the Mean = 10 / √100

Standard Deviation of the Mean = 10 / 10

Standard Deviation of the Mean = 1

Therefore, the standard deviation of the mean, or the standard error, in this situation is 1.