Final answer:
To find the cost for 6 tickets at a movie theater when 3 tickets cost $12.75, you double the amount, resulting in $25.50 for 6 tickets.
Step-by-step explanation:
The cost for 3 tickets is $12.75. To find the cost for 6 tickets, we can set up a proportional relationship because the number of tickets and the total cost are directly proportional. We can double the number of tickets and the cost will also double.
By knowing the cost for 3 tickets is $12.75, if we buy twice as many tickets (which is 6), we will pay twice as much. So, for 6 tickets, the cost would be:
$12.75 x 2 = $25.50
Thus, 6 tickets will cost $25.50.