For the Rule of 78, for a 12 month period, the last term in the sequence is 12 and the series sums to 78.
For an 14 month period, the last term is and the series sum is .
For a 16 month period, the last term is and the series sum is .
For a 20 month period, the last term is and the series sum is .

Joseph pays: $ 133.2

Step-by-step explanation:

Let's go through the problem. Joseph wants to buy a television that currently costs 40 percent off of it's original price of 740 dollars. First convert 40% to a decimal form. Moving the decimal two points right you would receive 0.4. Using this let's calculate the cost off of the television:

0.4 * 740 = 296 dollars

Now as this is the cost off of the television, to calculate the current cost of the television, let's simply subtract the cost off of the television from the original cost of the television:

740 - 296 = 444 dollars

Let's further read the problem. Joseph's dad agrees to buy the television if Joseph pays 30 percent of it's current cost. Here we can use a similar process as before. Convert 30% to a decimal form. Moving the decimal two points right you would receive 0.3. Using this let's calculate the cost Joseph has to pay for the television:

0.3 * 444 = 133.2 dollars