q The amount of time of an iphone battery lasts before it fails is normally distributed with mean 5.2 years and standard deviation of 1.3 years. Apple randomly selects 100 iPhones for testing. Is it a likely event that the mean lifetime of the iPhone's batteries will be greater than 5.5 years? how to proof this in mathematical form.

I got the answer is 0.0104 from the formula but in the calculator normalcdf i got .010508. which is 1.05% i need the normal cdf answer from the calculator. what is the exact one?