Lloyd is arranging his science project, math project, and art project on his desk. the tree diagram below shows the sample space. based on the tree diagram, what is the probability that the projects are in order of art, math, science? 1/6 2/6 3/6 4/6

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?