Given data,

Lower limit \(\displaystyle={13.05}\)

Upper limit \(\displaystyle={22.15}\)

Point estimate \(\displaystyle{x}={17.60}\)

\(\displaystyle{E}=?\)

Step 2

\(\displaystyle{E}={\frac{{{U}{L}-{L}{L}}}{{{2}}}}\)

\(\displaystyle={\frac{{{22.15}-{13.05}}}{{{2}}}}\)

\(\displaystyle{E}={4.55}\)