HELP ASAP 1.
(8,4)
(-4,2)
(4,-8)
(-8,4)
2.
(6,6)
(12,-12)
(-12,12)
(12,12)
3.
(-2,6)
(-4,12)
(4,12)
(12,-4)

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?

Me because i don't understand how to do it.: )

What is the length of segment tr?