Question 373749
You're basically finding the area under the curve of a standard normal distribution from -0.7727 to 1.5



So either use a table or a calculator to find that area. 



Preferably, a calculator will do. If you have a TI83, then simply hit "2nd" then "Vars" to get into the "Distribution" menu (which is for stats). Then find "normalcdf" and select that function.



So on your home screen, you should have "normalcdf(" (without quotes)


From there, type in -0.7727,1.5 (your boundaries). You can then optionally include the mean 0 and the standard deviation 1, but it's not necessary. Finally, close off the expression.



So you should have:  normalcdf(-0.7727,1.5) 

You can also type in : normalcdf(-0.7727,1.5,0,1) , but it's not necessary.



This then gives you 


normalcdf(-0.7727,1.5) = 0.71334



Note: For more info on the "normcdf" function, check out <a href="http://tibasicdev.wikidot.com/normalcdf">this page</a>



So the area under the standard normal curve form z=-0.7727 to z=1.5 is approximately 0.71334



So the probability that the assembly line time will be between 5 and 10 minutes is about 0.71334 (which is a 71.334% chance)



Alternatively, you can use the normal tables to give you the area. However, keep in mind that you're going to need to subtract.



If you need more help, email me at <a href="mailto:jim_thompson5910@hotmail.com?Subject=Algebra%20Help">jim_thompson5910@hotmail.com</a>


Also, feel free to check out my <a href="http://www.freewebs.com/jimthompson5910/home.html">tutoring website</a>


Jim