For a textile industry, the revenue of selling \( x \) tons of yarn is \( R(x) = 4x \) and the cost of producing \( x \) tons of yarn is \( C(x) = 10 + 2x + 3x^{2/3} \). The industry decided to calculate the break-even (when revenue is equal to the cost) for \( x \) tons of yarn using the Newton-Raphson method. Assuming the initial break-even of 8 tons, the break-even (in tons) after the first iteration is: