algebra 2
posted by Lea .
Students at a high school all took the same English test. The scores are approximately normally distributed with a mean of 77 and a standard deviation of 9. If 2500 students took the test, approximately how many scored above 86 or below 68%?

you buy a video game system for $500. the value of the video game system system decreases 25% each year . write an exponential model for the value of the videogame system in terms of the yeArs since the purchase