Wednesday

April 16, 2014

April 16, 2014

Posted by **Maddie Liguori** on Tuesday, March 1, 2011 at 12:27am.

a)If we randomly sample 25 college students, what is the probability that the average income of our sample is less than $4,000?

b)If we randomly sample 9 college students, what is the probability that the average income is between $5000 and $20,000?

- statistics -
**PsyDAG**, Tuesday, March 1, 2011 at 9:16pmZ = (mean1 - mean2)/standard error (SE) of difference between means

SEdiff = √(SEmean1^2 + SEmean2^2)

SEm = SD/√(n-1)

If only one SD is provided, you can use just that to determine SEdiff.

Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportions related to the Z scores.

**Related Questions**

Statistics - Suppose the mean income of 35-year-olds in the U.S. is $25,000. A ...

Statistics - I am not sure how to even get started on this question could ...

Statistics - The standard deviation of GPAs (grade point averages) of all male ...

statistics - The Survey of Study Habits and Attitudes (SSHA) is a psychological ...

statistics - Suppose a random sample of 25 students is selected from a community...

Econ/statistics - The monthly earnings of teachers is normally distributed with ...

statistics - Suppose a college's SAT scores are normally distributed with mean ...

statistics - The Survey of Study Habits and Attitudes (SSHA) is a psychological ...

statistics - College students average 7.8 hours of sleep per night with a ...

statistics - A survery of 80 randomly selected companies asked them to report ...