The life of a fully charged cell phone battery is normally distributed with a mean of 12 hours and a standard deviation of half an hour. What percent of batteries last less than 11 hours? ​

Which statement about the relative areas of δabc and δxyz is true? the area of δabc > the area of δxyz the area of δabc < the area of δxyz the area of δabc = the area of δxyz more information is needed to compare.

Estimate the area under the curve f(x) = 16 - x^2 from x = 0 to x = 3 by using three inscribed (under the curve) rectangles. answer to the nearest integer.

I’m still confused on how to work the percentages