ILL MAKE YOU BRAINLIST. Answer all 3 please. SHOW ALL YOUR WORK. Find the radius?

1. diameter= 16.6 km

2. circumference= 69.1 in

3. area= 307.9 in2
a) 9.9 in
b) 98 in
c) 10.2 in
d) 5 in
​

Can someone me out here number 4 plz

The number of 8th graders who responded to a poll of 6th grade and 8 th graders was one fourtg of the number of 6th graders whi responded if a total of 100 students responddd to the poll how many of the students responded were 6 th graders

Find the value of x in each case. give reasons to justify your solutions! d q ∈ pr