1 cup is equal to 8 oz, so
3 cups x 8 = 24 oz.
you'll do the same for the two cups
2 x 8 = 16 oz
so adding them all together will be
24 + 6 + 16 + 9 = 55 total oz.
You must first normalize this in order to use a Z-score table. To convert what you have into a Z score you must use this formula: (x- mean) /standard deviation. In your case (334-310)/12=2. So now you want the probability that a score is greater than 334, which in turn means you want P(Z>2)=1-P(Z<2)=1-.9772=0.0228=2.28%.
The sales tax is $7.67
In total, with the sales tax, the phone would be $92.65
