Westonci.ca makes finding answers easy, with a community of experts ready to provide you with the information you seek. Discover comprehensive solutions to your questions from a wide network of experts on our user-friendly platform. Explore comprehensive solutions to your questions from knowledgeable professionals across various fields on our platform.

Ross Hopkins, president of Hopkins Hospitality, has developed the tasks, durations, and predecessor relationships in the following table for building new motels.

\begin{tabular}{|c|c|c|c|c|c|c|c|c|c|}
\hline
\multirow[b]{2}{}{Activity} & \multicolumn{3}{|c|}{Time (weeks)} & \multirow{2}{}{\begin{tabular}{l}Immediate\\Predecessor(s)\end{tabular}} & \multirow[b]{2}{}{Activity} & \multicolumn{3}{|c|}{Time (weeks)} & \multirow{2}{}{\begin{tabular}{l}Immediate\\Predecessor(s)\end{tabular}} \\
\hline
& [tex]$a$[/tex] & [tex]$m$[/tex] & [tex]$b$[/tex] & & & [tex]$a$[/tex] & [tex]$m$[/tex] & [tex]$b$[/tex] & \\
\hline
[tex]$\bar{A}$[/tex] & 4 & 9 & 10 & - & [tex]$G$[/tex] & 3 & 3 & 4 & [tex]$\overline{C, E}$[/tex] \\
\hline
[tex]$B$[/tex] & 2 & 9 & 24 & [tex]$A$[/tex] & [tex]$H$[/tex] & 2 & 2 & 2 & [tex]$F$[/tex] \\
\hline
[tex]$C$[/tex] & 9 & 12 & 18 & [tex]$A$[/tex] & [tex]$I$[/tex] & 5 & 5 & 5 & [tex]$F$[/tex] \\
\hline
[tex]$D$[/tex] & 4 & 7 & 10 & [tex]$A$[/tex] & [tex]$J$[/tex] & 6 & 7 & 14 & [tex]$D, G, H$[/tex] \\
\hline
[tex]$E$[/tex] & 1 & 3 & 4 & [tex]$B$[/tex] & [tex]$K$[/tex] & 1 & 1 & 4 & [tex]$I, J$[/tex] \\
\hline
[tex]$F$[/tex] & 5 & 8 & 20 & [tex]$\overline{C, E}$[/tex] & & & & & \\
\hline
\end{tabular}

a) The expected (estimated) time for activity [tex]$C$[/tex] is [tex]$\square$[/tex] weeks. (Round your response to two decimal places.)


Sagot :

To find the expected (estimated) time for activity \( C \), we use the PERT (Program Evaluation and Review Technique) formula for the expected time:

[tex]\[ TE = \frac{a + 4m + b}{6} \][/tex]

where
- \( a \) is the optimistic time,
- \( m \) is the most likely time, and
- \( b \) is the pessimistic time for the activity.

For activity \( C \), the given times are:
- \( a = 9 \) weeks (optimistic time),
- \( m = 12 \) weeks (most likely time),
- \( b = 18 \) weeks (pessimistic time).

Plugging these values into the PERT formula, we get:

[tex]\[ TE = \frac{9 + 4(12) + 18}{6} \][/tex]

First, calculate the values inside the parentheses:

[tex]\[ 9 + 4(12) + 18 = 9 + 48 + 18 = 75 \][/tex]

Next, divide the sum by 6:

[tex]\[ TE = \frac{75}{6} \approx 12.5 \][/tex]

Hence, the expected (estimated) time for activity [tex]\( C \)[/tex] is [tex]\( 12.5 \)[/tex] weeks.