Chapter 6.4, Problem 23IP

To determine

To find: Number of calls telethon received on second night.

Answer to Problem 23IP

Number of calls telethon received on second night $=x=3088$

Explanation of Solution

Given information:

Number of viewers called on first night = Original value $=3860$

The next night there was a $20\%$ decrease in the number of calls from the first night.

Percent change $=20\%$ and percent is decrease.

Percent change $=\frac{A}{O}\times 100$

Where

  $A=$ Absolute value.

  $O=$ Actual value.

From given information

Number of viewers called on first night = Original value $=3860$

The next night there was a $20\%$ decrease in the number of calls from the first night.

Percent change $=20\%$ and percent is decrease.

Let $\text{'}x\text{'}$ be the number of viewers called on next day night that means final value.

Amount of change = Final value $-$ Original value

  $\Rightarrow A=x-3860$

Therefore,

Percent change $=\frac{x-3860}{3860}\times 100$

  $\Rightarrow$$-20=\frac{100x-386000}{3860}$

  $\begin{array}{l}\Rightarrow -20=\frac{100x-386000}{3860}\\ \Rightarrow 100x-386000=\left(-20\right)\times 3860\\ \Rightarrow 100x-386000=-77200\\ \Rightarrow 100x=386000-77200\\ \Rightarrow 100x=308800\\ \Rightarrow x=\frac{308800}{100}\\ \Rightarrow x=3088\end{array}$

Therefore,

Number of viewers called on second night = $x=3088$

Number of calls telethon received on second night $=x=3088$