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

River Division Stream Division

Sales revenue $ $1,215,000$ $ $1,808,000$

Cost of goods sold and operating expenses $900,0001,289,000$

Net operating income $ $315,000$ $ $519,000$

Average invested assets $ $1,000,000$ $ $1,430,000$

The company$$s hurdle rate is $6\mathrm{.}51$ percent.

Required:

$1)$ Calculate return on investment $($ROI$)$ and residual income for each division for last year.

$2)$ Recalculate ROI and residual income for each division for each independent situation that follows:

a$)$ Operating income increases by $9$ percent.

b$)$ Operating income decreases by $11$ percent.

c$)$ The company invests $$252,000$ in each division, an amount that generates $$107,000$ additional income per division.

d$)$ Coolbrook changes its hurdle rate to $4\mathrm{.}51$ percent.

Note: Enter your ROI answers as a percentage rounded to two decimal places, $($i$.$e$.,0\mathrm{.}1234$ should be entered as $12\mathrm{.}34\%.).$ Loss amounts should be indicated with a minus sign.