Please help me with 1,2,3,4 and show me how you get it the answers please I really need help can someone help me

Rose drew a regression line for this paired data set. her line passed through (1, 2) and (3, 5) . what is the equation of rose's regression line?

Kayla and alberto are selling fruit for a school fundraiser. customers can buy small boxes of grapefruit and large boxes of grapefruit. kayla sold 3 small boxes of grapefruit and 1 large box of grapefruit for a total of $65. alberto sold 1 small box of grapefruit and 1 large box of grapefruit for a total of $55. what is the cost each of one small box of grapefruit and one large box of grapefruit?

The curved part of the figure is the semicircle what is the best approximation for the area of this figure