Question

jillian is trying to determine what helium tank pressure she needs to fill balloons for the student council dance. fill in the unknown numbers in the table until you find the best answer to the question. which cylinder pressure will jillian need if she plans to fill 90 balloons? tank pressure and balloon quantity pressure in the helium cylinder (psi) number of 9 - inch balloons 100 30 150? 200? 250? 300?

Explanation:

Step1: Find the ratio between pressure and number of balloons

We assume there is a proportional relationship. Given 100 psi fills 30 balloons, the ratio is $\frac{100}{30}=\frac{10}{3}$ psi per balloon.

Step2: Calculate the pressure for 90 balloons

Let $P$ be the pressure. Using the ratio, $P=\frac{10}{3}\times90$.
$P = 300$ psi.

Answer:

300 psi