Question

The manager of a grocery store has taken a random sample of 100 customers. The average length of time it took these 100 customers to check out was 3 minutes. It is known that the standard deviation of the population of checkout times is 1 minute. The standard error of the mean equals?

Answer 1

The standard error of the mean equals 0.1

Explanation:

We are given the following in the question:

Sample mean,
`\bar{x}` = 3 minutes

Sample size, n = 100

Population standard deviation, σ = 1 minute

Formula:

`\text{Standard Error} = \displaystyle(\sigma)/(√(n))\\\\= (1)/(√(100)) = (1)/(10) = 0.1`

Thus, standard error of the mean equals 0.1