A recent study of the lifetimes of cell phones found the average is 24.3 months. The standard deviation is 2.6 months. If a company provides its 33 employees with a cell phone, how many of these phones lasts less than 23.8 months. Assume cell phone life is a normally distributed variable. I got 0.1357
It asked me to round it to the whole number it will be 0.1357 x 100= 13.57 so the final answer is 14 , but the computer marked it wrong any suggestions.