WILL GIVE BRAINLIEST FOR RIGHT ANSWER Divide

Ijust need to see how to do this. so you don’t have to answer all of them just a step by step explanation of one.

Can you me find the missing length. i attached an image.

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?