Answer:
First, let's find the amount of sales tax:
Sales tax = cost of the game * sales tax rate
Sales tax = $15 * 7% = $1.05
Then, we can calculate the total cost of the board game:
Total cost = cost of the game + sales tax
Total cost = $15 + $1.05 = $16.05
Therefore, the total cost of the board game, including sales tax, is $16.05.