If y varies inversely as x and y is 6 when x is 12 what is x when y is 14.4

1. To solve this problem and calculate the value of  "x" when "y" is 14.4, you must apply the following formulla:
 
 y=k/x
 
 k:  It is the constant of variation or constant of proportionality.
 
 2. So, keeping this on mind, you must calculate the value o the constant of variation "k", with the values given in the problem. Then, you have:
 
 k=yx
 k=(6)(12)
 k=32
 
 3. Now, you can apply the equation y=k/x and clear the "x" to find its value:
 
 yx=k
 x=k/y
 
 k=32
 y=14.4
 
 4. Then, you have:
 
 x=32/14.4
 
 5. Therefore, the answer is:
 
 x=2.22

Answer: r=4.5  feetexplanation: radius  r  is half of the diameter  d,⇒r=d2=92=4.5  feetidk i could be wrong