## DarkendSinz30 2 years ago I really need help in understanding this??

1. DarkendSinz30

Consider a population with u=70.2 and o=4.61. (A) Calculate the z-score for x=73.2 from a sample of size 10. (B) Could this z-score be used in calculating probabilities using Table 3 in Appendix B of the text? Why or why not?

2. CliffSedge

I take it u=µ and o=σ? I can't help you with what Appendix B is in your book, but I can show you the z-score formula.

3. DarkendSinz30

Yeah the symbols are that way and I think I have the z-score formula but could use a refresher

4. CliffSedge

$\huge z=\frac{x-µ}{s_x}$ $\huge s_x = \frac{σ}{√n}$

5. DarkendSinz30

I have Appendix B table 3 pulled up from my book so if we can get the problem solved I can do the rest please

6. CliffSedge

Cool. Use those formulas, and you should be fine. Try here for more info: http://stattrek.com/probability-distributions/standard-normal.aspx?tutorial=ap http://stattrek.com/sampling/sampling-distribution.aspx?Tutorial=AP

7. DarkendSinz30

Thank you so much so far everything I have looked at including my text book has been confusing.

8. CliffSedge

Stats is a messy place. It takes a strong combination of mathematical skill and good ol' common sense. Good luck!