now whenever you get a number greater than 3.4 or is bigger than the table in your textbook you assume 0.99999 now we are looking for someone who spends at least 158 minutes so we are looking for a person who spends 158 minutes or more which means were looking for the area to the right of the curve 1-0.99999=0.00001 then X100 for a percentage which is 0.001% which basically means noone spends that amount of time on social media.