R in this equation refers to the radius
The history museum is less that 9 4/5 miles. 9/10 means that the 9 3/4 mile is broken up into 10 equal parts and the distance to the museum is only 9 of those parts. 9 3/4 (9.8) divided by 10 equals 98/100 (.98)
98/100 x 9 = 882/100 or 8.82
Justin's house is 8.82 miles from the museum.
One thing to bear in mind with trigonometric expressions is that, the exponent location is next to the function name, instead of the whole expression, though it applies to the whole thing, namely cos²(x), is really [ cos(x) ]², and that matters for using the chain rule.
Answer:
the answer is 480 cubic feet
100 / 60 = 1.66666667 , 1.66666667 x 39 = 65