Question 1184074
here's a reference.


<a href = "https://www.purplemath.com/modules/variatn.htm" target = "_blank">https://www.purplemath.com/modules/variatn.htm</a>


this problem is in the reference.
it's on the third page i believe.
it's good for you to read each page though, as it contains good information on how to solve the different variation formulas.


in your problem, the formula is R = k * L / d^2


R is the resistance
L is the length of the wire.
d is the diameter of the wire.
k is the constant of variation.


when L = 4000 feet and d = .18 inches, R = 7867 ohms.


R = k * L / d^2 becomes:


7867 = k * 4000 / .18^2


solve for k to get:


k = 7867 * .18^2 / 4000 = .0637227.


k, being the constant of variation, will stay the same and will be used to solve the question.


the question is:


what is the resistance of 4300 feet of the same type of wire with a diameter of .27 inches.


R = k * L / d^2 becomes:


R = .0637227 * 4300 / .27^2.


solve for R to get:


R = 3758.677778.


round to the nearest hundredth to get:


R = 3758.68.


that's your answer.


the link to each page in the reference is on the bottom of each page of the reference.


if you want to go directly to the third page, then click on <a href = "https://www.purplemath.com/modules/variatn3.htm" target = "_blank">https://www.purplemath.com/modules/variatn3.htm</a>


but then, you'll miss all the good stuff on pages 1 and 2.