Pembahasan Ujian PAI: A50 – No. 28 – Mei 2017

• \({\rho _1} = \frac{{{\phi _1}}}{{1 – {\phi _2}}}\)
• \({\rho _2} = {\phi _2} + \frac{{\phi _1^2}}{{1 – {\phi _2}}}\)

Dengan mensubstitusikan persamaan di atas ke persamaan 2
\(0.65 = \frac{{0.75 – {\phi _1}}}{{0.75}} + \frac{{\phi _1^2}}{{1 – \frac{{0.75 – {\phi _1}}}{{0.75}}}}\) \(0.65 = \frac{{0.75 – {\phi _1}}}{{0.75}} + \frac{{0.75\phi _1^2}}{{{\phi _1}}}\) \(0.65 = \frac{{0.75 – {\phi _1}}}{{0.75}} + 0.75{\phi _1}\) \(0.4875 = 0.75 – {\phi _1} + 0.5625{\phi _1}\) \(0.4375{\phi _1} = 0.2625\) \({\phi _1} = 0.6\)