Find an equation in standard form for the ellipse with the vertical major axis of length 10 and minor axis of length 8. x squared divided by 25 plus y squared divided by 16 equals 1
x squared divided by 5 plus y squared divided by 4 equals 1
x squared divided by 4 plus y squared divided by 5 equals 1
x squared divided by 16 plus y squared divided by 25 equals 1

1. according to the internal revenue service, the mean tax refund for the year 2007 was $2,708. assume the standard deviation is $650 and that the amounts refunded follow a normal probability distribution. a. what percent of the refunds are more than $3,000? b. what percent of the refunds are more than $3,000 but less than $4,000? c. what percent of the refunds are less than $2,000?