$\text{a)}$  

$\text{b)}$  

Pomiar 1.:

${\text{R}}_1=\frac{{\text{U}}_1}{{\text{I}}_1}=\frac{1,2\text{V}}{175\mu \text{A}}=\frac{1,2\text{V}}{0,000175\text{A}}\approx 6857\Omega$   

${\text{R}}_1\approx 6,86\text{k}\Omega$  

Pomiar 2.:

${\text{R}}_2=\frac{{\text{U}}_2}{{\text{I}}_2}=\frac{1,7\text{V}}{250\mu \text{A}}=\frac{1,7\text{V}}{0,00025\text{A}}=6800\Omega$  

${\text{R}}_2=6,8\text{k}\Omega$  

Pomiar 3.:

${\text{R}}_3=\frac{{\text{U}}_3}{{\text{I}}_3}=\frac{2,3\text{V}}{340\mu \text{A}}=\frac{2,3\text{V}}{0,00034\text{A}}\approx 6764\Omega$   

${\text{R}}_3\approx 6,76\text{k}\Omega$    

Pomiar 4.:

${\text{R}}_4=\frac{{\text{U}}_4}{{\text{I}}_4}=\frac{2,8\text{V}}{410\mu \text{A}}=\frac{2,8\text{V}}{0,00041\text{A}}\approx 6829\Omega$  

${\text{R}}_4\approx 6,83\text{k}\Omega$  

Pomiar 5.:

${\text{R}}_5=\frac{{\text{U}}_5}{{\text{I}}_5}=\frac{3,3\text{V}}{480\mu \text{A}}=\frac{3,3\text{V}}{0,00048\text{A}}=6875\Omega$  

${\text{R}}_5\approx 6,88\text{k}\Omega$  

$\text{c)}$  

Średnia wyników wynosi:

$\text{R}=\frac{{\text{R}}_1+{\text{R}}_2+{\text{R}}_3+{\text{R}}_4+{\text{R}}_5}{5}=\frac{6,86\text{k}\Omega +6,8\text{k}\Omega +6,76\text{k}\Omega +6,83\text{k}\Omega +6,88\text{k}\Omega }{5}=\frac{34,13\text{k}\Omega }{5}$  

$\text{R}\approx 6,80\text{k}\Omega$