Answered

The sample size is 144, and the mean of the entire sample is 4.8. If the standard deviation is 1.5, what is the standard error to three decimal places?



Answer :

Certainly! Let's solve the problem step-by-step.

1. Given information:
- Sample size ([tex]\( n \)[/tex]) = 144
- Standard deviation ([tex]\( \sigma \)[/tex]) = 1.5

2. Objective:
- To find the standard error (SE) rounded to three decimal places.

3. Formula for Standard Error:
[tex]\[ SE = \frac{\sigma}{\sqrt{n}} \][/tex]

4. Calculation:

- First, calculate the square root of the sample size ([tex]\( n \)[/tex]):
[tex]\[ \sqrt{n} = \sqrt{144} = 12 \][/tex]

- Next, divide the standard deviation ([tex]\( \sigma \)[/tex]) by the square root of the sample size ([tex]\( \sqrt{n} \)[/tex]):
[tex]\[ SE = \frac{\sigma}{\sqrt{n}} = \frac{1.5}{12} = 0.125 \][/tex]

5. Result:

The standard error is:
[tex]\[ SE = 0.125 \][/tex]

So, the standard error to three decimal places is [tex]\( 0.125 \)[/tex].