Solution.
Calculate the standard deviation
The formula is given below
[tex]\begin{gathered} \sigma=4 \\ \mu=16 \\ \end{gathered}[/tex][tex](A)\text{ }Z_{14}=\frac{14-16}{4}=-0.5[/tex]P(x>-0.5) = 0.69146
In percentage, P(x>Z) = 69.15% (2 decimal places)
THE PERCENT OF CUSTOMERS WHO WAIT FOR AT LEAST 14 MINUTES
BEFORE BEING SEATED is 69.15%
(B)
[tex]\begin{gathered} Z_{12}=\frac{12-16}{4}=-1 \\ \end{gathered}[/tex][tex]Z_{24}=\frac{24-16}{4}=2[/tex][tex]\begin{gathered} P\left(-1Thus, THE PERCENT OF CUSTOMERS WHO WAIT BETWEEN 12 AND 24 MINUTES BEFORE BEING SEATED is 81.86%(C)
[tex]Z_{21}=\frac{21-16}{4}=1.25[/tex][tex]\begin{gathered} P\left(x>1.25\right)=0.10565 \\ In\text{ percentage, we have 10.57\% \lparen2 decimal places\rparen} \end{gathered}[/tex]Thus, THE PERCENT OF CUSTOMERS WHO WAIT AT LEAST 21 MINUTES BEFORE BEING SEATED is 10.57%
