*7.108 It is required to design the bias circuit of Fig. 7.52 for a BJT whose nominal β =100. (a) Find the largest ratio RB/RE that will guarantee IE remains within ±5% of its nominal value for β as low as 50 and as high as 150. (b) If the resistance ratio found in (a) is used, find an expression for the voltage VBB ≡ VCCR2/R1 +R2 that will result in a voltage drop of VCC/3 across RE. (c) For VCC = 5 V, find the required values of R1, R2, and RE to obtain I E = 0.5 mA and to satisfy the requirement for stability of IE in (a). (d) Find RC so that VCE = 1.0 V for β equal to its nominal value. Check your design by evaluating the resulting range of I E.