Question
assume that blood pressure readings are normally distributed with a mean of 111 and standard deviation of 7. A researcher wishes to select people for a study but wants to exclude the top and bottom 10 percent. What would be the upper and lower readings to qualify people to participate in the study?
Answers
Steve
the central 80% of the Z table lies within µ ± 1.282σ
So, plug in your numbers
You can play around with Z table stuff at this excellent site:
http://davidmlane.com/hyperstat/z_table.html
So, plug in your numbers
You can play around with Z table stuff at this excellent site:
http://davidmlane.com/hyperstat/z_table.html