Please help i dont know what im doing at all

Aline has a slope of 1/4 and passes through point (0.4,-1/2). what is the value of the y-intercept?

Laura read 1/8 of a comic book in 2 days. she reads the same number of pages every day. what part of the book does she read in a week

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?