Answer
a. $150000\ \Omega $.
b. $900000\ \Omega.$
c. $600000\ \Omega.$
d. $ 300000\ \Omega$.
Work Step by Step
a. The black fourth band indicates a tolerance of $\pm 20\%$.
$$20\% \times 750000\Omega = (0.20)(750000\Omega) =150000\ \Omega .$$
That is, the tolerance is $150000\ \Omega $.
b. The upper limit is
$$750000\ \Omega + 150000\ \Omega=900000\ \Omega.$$
c. The lower limit is
$$750000\ \Omega - 150000\ \Omega=600000\ \Omega.$$
d. The tolerance interval is then $$
900000\ \Omega-600000\ \Omega= 300000\ \Omega
.$$
