I am looking for help solving the below parts in the attached photo. The copy and pasted section below goes along with the problems. Thank you in advance!

Coolbrook Company has the following information available for the past year:

River DivisionStream DivisionSales revenue$1,210,000$1,814,000Cost of goods sold and operating expenses886,0001,283,000Net operating income$324,000$531,000Average invested assets$1,190,000$1,560,000

The company's hurdle rate is 6.26 percent.

b. Operating income decreases by 8 percent. o. The company invests $240 .000 in each division, on amount that generates $100,000 additional income per division. d. Coolbrdok changes its hurdle rate to 4.26 percent. Residual Income {Loss}