To determine how much mass the pre-1982 pennies contribute to the weighted average mass, we need to follow these steps:
1. Identify the number of pre-1982 pennies.
- From the table, we see that there are 8 pre-1982 pennies.
2. Determine the average mass of a pre-1982 penny.
- According to the table, the average mass of a pre-1982 penny is 3.1 grams.
3. Calculate the total mass of all pre-1982 pennies combined.
- To find this, we multiply the number of pre-1982 pennies by their average mass:
[tex]\[
\text{Total mass of pre-1982 pennies} = \text{Number of pre-1982 pennies} \times \text{Average mass of a pre-1982 penny}
\][/tex]
- Substituting the given values:
[tex]\[
\text{Total mass of pre-1982 pennies} = 8 \times 3.1
\][/tex]
4. Perform the multiplication.
- [tex]\[
8 \times 3.1 = 24.8
\][/tex]
Thus, the pre-1982 pennies contribute 24.8 grams to the weighted average mass.
