Wednesday

July 23, 2014

July 23, 2014

Posted by **Kristin** on Friday, September 28, 2012 at 4:07pm.

What is the probability that the average of this sample will be within 1.4 STANDARD ERRORS of the population mean?

- statistics -
**MathGuru**, Friday, September 28, 2012 at 6:24pmmean = 67.6

standard deviation = 4.2

sample size = 51

Standard error: sd/√n = 4.2/√51 = 0.588

Next step:

67.6 - 1.4 = 66.2

67.6 + 1.4 = 69

Use z-scores:

z = (x - mean)/sd

Therefore:

z = (66.2 - 67.6)/0.588 = -2.38

z = (69 - 67.6)/0.588 = 2.38

Finally:

Check z-table for the probability between the above two z-scores. This will be your answer.

I hope this helps.

**Related Questions**

statistics - The average temperature in households is 67.6 degrees F. The ...

Stat - A random sample of 50 households in community A has a mean household ...

Statistics - 3. A telephone company wants to estimate the porportion of ...

Statistics - Data from the latest census was analyzed. It was determined that ...

statistics - Data from the latest census was analyzed. It was determined that ...

statistics - A TV pollster believes that 75% of all TV households would be tuned...

Statistics - 1. The sociologist surveyed the households in a small town. The ...

statistics - A TV pollster believes that 75% of all TV households would be tuned...

Math - A random survey of 500 households determines that 20% of the households ...

Statistics - A survey organization takes a simple random sample of 625 ...