Out of the 80 customers surveyed, 65 of them liked the iphone the most. if 500 people were given the same survey, predict how many would prefer an iphone?

406 would be expected to prefer the iPhone.

Based on the survey, the probability that someone would prefer an iPhone is 65/80.  Multiplying this probability by 500, we have

65/80(500) = 406.25 ≈ 406.

40 & 50 in the right corner are the complementary angles as when placed in a sum (added together) they make 90°