The chair's shadow is 72/48 = 1.5 times as long as the lifeguard's shadow. Since shadow length is presumed proportional to height, we expect the lifeguard chair to be 1.5 times as tall as the lifeguard.
1.5(76 in) = 114 in = 9 ft 6 in . . . height of lifeguard chair
The slope equation is y=mx+b where m is the slope and b is the y intercept. After plugging the numbers into the equation you should get y=-2x+6. Hope this helps!
