Chapter 12.1, Problem 3P

To determine

To check: which of the city has the greatest average number of cloudy days.

Answer to Problem 3P

The town will hold a runoff.

Explanation of Solution

Given:

From problem 3,

The given picture shows the average number of clear and cloudy days in full year:

Calculation:

Use matrices to organize the information:

The below matrix shows the clear and cloudy day in the month of September-February.

  $\left[\begin{array}{l}10241\\ 5348\\ 5582\end{array}\right]$

The below matrix shows the clear and cloudy day in the month of March-August.

  $\left[\begin{array}{l}11027\\ 3159\\ 4583\end{array}\right]$

Now, add the corresponding elements:

  $\left[\begin{array}{l}10241\\ 5348\\ 5582\end{array}\right]+\left[\begin{array}{l}11027\\ 3159\\ 4583\end{array}\right]=\left[\begin{array}{l}21268\\ 74117\\ 100165\end{array}\right]$

Here, the second column of the matrix represents the average number of cloudy days in a cloudy year for each city. The greatest number in that column is 165, which corresponding to Portland.

Therefore, Portland has the greatest average number of cloudy days.