A box contains two different-shaped shirt buttons: square and circle. What is the weighted average of the buttons in the sample data given?

[tex]\[
\begin{tabular}{|c|c|c|c|}
\hline
Sample & \begin{tabular}{c}
Abundance \\
(\%)
\end{tabular} & \begin{tabular}{c}
Mass of \\
button (g)
\end{tabular} & Mass (g) \\
\hline
Square & 32 & 1.0 & \\
\hline
Circle & 68 & 1.6 & \\
\hline
\end{tabular}
\][/tex]



Answer :

To find the weighted average of the buttons in the given sample data, you need to follow these steps:

### 1. Convert the percentages to proportions
The abundance of the square buttons is given as 32%, which can be converted to a proportion by dividing by 100:
[tex]\[ \text{Abundance of square buttons} = \frac{32}{100} = 0.32 \][/tex]

Similarly, the abundance of the circle buttons is given as 68%, which can be converted to a proportion by dividing by 100:
[tex]\[ \text{Abundance of circle buttons} = \frac{68}{100} = 0.68 \][/tex]

### 2. Identify the masses of each type of button
The mass of a square button is given as 1.0 grams:
[tex]\[ \text{Mass of square button} = 1.0 \, \text{g} \][/tex]

The mass of a circle button is given as 1.6 grams:
[tex]\[ \text{Mass of circle button} = 1.6 \, \text{g} \][/tex]

### 3. Calculate the weighted average mass
The weighted average mass is calculated by multiplying the proportion of each type of button by its respective mass and then summing these values:

[tex]\[ \text{Weighted average mass} = (\text{Abundance of square buttons} \times \text{Mass of square button}) + (\text{Abundance of circle buttons} \times \text{Mass of circle button}) \][/tex]

Substitute the known values:

[tex]\[ \text{Weighted average mass} = (0.32 \times 1.0) + (0.68 \times 1.6) \][/tex]

### 4. Compute the individual contributions to the weighted average

First, calculate the contribution of the square buttons:

[tex]\[ 0.32 \times 1.0 = 0.32 \][/tex]

Next, calculate the contribution of the circle buttons:

[tex]\[ 0.68 \times 1.6 = 1.088 \][/tex]

### 5. Sum the contributions to find the weighted average mass

Adding the contributions together gives us:

[tex]\[ 0.32 + 1.088 = 1.408 \][/tex]

Thus, the weighted average mass of the buttons in the sample data is:

[tex]\[ \boxed{1.408 \, \text{g}} \][/tex]

So, the weighted average mass of the buttons in the sample data is 1.408 grams.