Question

among 420 randomly selected employees at a company, the mean number of hours of overtime worked per month is 10 hours and the standard deviation is 1.6. what is the margin of error, assuming a 99% confidence level?

confidence level (%) | 90 | 95 | 99
--- | --- | --- | ---
\\(z^*\\)-score | 1.645 | 1.96 | 2.58

• 4.12
• 0.01
• 0.20
• 20.5

Explanation:

Identify the given values and formula

Using the Margin of Error Calculation knowledge point

$$
LATEXBLOCK0
$$

Calculate the standard error of the mean

$$
LATEXBLOCK1
$$

Calculate the margin of error

$$
LATEXBLOCK2
$$

Rounding to two decimal places, the margin of error is approximately \(0.20\).

Answer:

• 4.12
• 0.01
• 0.20 (Correct answer)
• 20.5