Final answer:
To find out how many bottles of sparkling water are needed for a party of 145 guests, we can use a proportion. The party planner must purchase 58 bottles.
Step-by-step explanation:
To figure out how many bottles of sparkling water the party planner must purchase, we can use a proportion. We know that there are 2 bottles of sparkling water per 5 guests. So, for every 5 guests, we need 2 bottles. To find out how many bottles are needed for 145 guests, we set up the proportion:
2 bottles / 5 guests = x bottles / 145 guests
Cross-multiplying, we get:
5x = 2 * 145
Simplifying, we find:
x = (2 * 145) / 5 = 58
So, the party planner must purchase 58 bottles of sparkling water for the party of 145 guests.