Hi, here is the solution...
Part B)
The Navy Pier Ferris has the circumference is 56% of the circumference of the first Ferris wheel.
The Navy Pier Ferris Circumference = 439.6 feet
Let's assume "x" be circumference of first Ferris wheel.
56% of x = 439.6
0.56 x = 439. 6 [56% = 0.56]
x = 439.6/0.56
x = 785.
Therefore, the circumference of the first Ferris wheel is 785.
It is diameter = 785/3.14 = 250 feet
So it is radius = 250/2 = 125 feet.
Part C)
The circumference = 785 feet
Speed = Distance/Time
Speed = 785/9
Speed = 87.2 feet per minute.
That's it. Hope you will understand the steps.
Thank you. :)