Answer: The ratio of the total cost of the party in 2007 to the total cost of the party in 2008 = 1: 4
Explanation:
It is given that Kyle's birthday party in 2007 cost $d$ dollars per person and $p$ people attended.
Then , the total cost of the party = Cost per person x Number of people attended.
For 2007, Total cost = d x p = dp (1)
In 2008, the cost per person doubled and the number of people attending the party also doubled.
i.e. Cost per person = 2d
Number of people attended = 2p
For 2008, Total cost = 2d x 2p = 4dp (2)
From (1) and (2) , the ratio of the total cost of the party in 2007 to the total cost of the party in 2008 will be :

Cancel pd from the numerator and the denominator , we get

Hence, the ratio of the total cost of the party in 2007 to the total cost of the party in 2008 = 1: 4