Suppose that a potato chip brand labels its bags as having 9-ounces. The manufacturing process produces chip weights that are normally distributed with mean 9.12 ounces and standard deviation .05 ounce. What percent of bags weigh less than 9.02 ounces?
Now what I want to know is, is it possible to find this using a TI-84? I know how to find data points given the percentile but not the other way around...any help is appreciated. Thank You!

(If you want to be super nice, you can also show me how to actually do it :3)

Question

Suppose that a potato chip brand labels its bags as having 9-ounces. The manufacturing process produces chip weights that are normally distributed with mean 9.12 ounces and standard deviation .05 ounce.  What percent of bags weigh less than 9.02 ounces?
Now what I want to know is, is it possible to find this using a TI-84? I know how to find data points given the percentile but not the other way around...any help is appreciated. Thank You!

(If you want to be super nice, you can also show me how to actually do it :3)

perl · Answer

you can use normalcdf on TI 84

perl · Answer

TI 84 : 
2nd -> VARS -> 2:normalcdf(

Now you will see on the home screen
normalcdf( 
Now the inputs are  normalcdf( lowerbound, upperbound, mean, standard deviation)
 
normalcdf ( -1x10^99, 9.02, 9.12, .05)  = .02275

anonymous · Answer

oh I see!!  I was using normalcdf for things like (what is the percentile for weights between this and that) but I didn't know what to do when you only had one number. Making the lower bound practically negative infinity makes a lot of sense XD. 
I'm guessing if it's "more than 9.02 ounces" you would just put 9.02 as the lower bound and 1x10^99 the upperbound right?
Thank you so much!! XD I was afraid no one would answer haha.