To solve: The proportion 53=40x.

Question

Laith Petty · Accepted Answer

Approach:
The quotient of two numbers is called a ratio.
Ex. $\frac{2}{3}$ .
The ratio is no different from a fraction, except that a ratio is sometimes written using notation other than fractional notation.
Ex. The ratio of 5 to 7 can be written as fractional notation $\frac{5}{7}$ or colon notation $5 : 7$ .
If a ratio contains decimal numbers or mixed numbers, then the ratio can be written only by the ratio of whole numbers.
Ex. $5.7 : 3$ can be written as $\frac{57}{30}$
A proportion is a statement that two ratios or rates are equal.
Ex. If $\frac{a}{b}$ and $\frac{c}{d}$ are two ratios, then $\frac{a}{b} = \frac{c}{d}$ is a proportion.
If the cross products are not equal, the proportion is true.
Ex, If $a \cdot d = b \cdot c$ , then it is true.
If the cross products are not equal, the proportion is false.
Ex. If $a \cdot d \neq b \cdot c$ , then it is false.
When one number of proportion is unknown, then use cross products to find the unknown number.
Ex. Find the unknown number x in the proportion $\frac{4}{2} = \frac{20}{x}$ . It can be found by cross product. That is, $x = 10$ .
Calculation:
Determine the value of x in the proportion $\frac{5}{3} = \frac{40}{x}$ by using the cross product.
$\frac{5}{3} = \frac{40}{x}$
$5 \cdot x = 40 \cdot 3$
$x = \frac{120}{5}$
$x = 24$
Therefore, the value is $x = 24$ .
The final Statement:
The value of x in the proportion $\frac{5}{3} = \frac{40}{x}$ is $x = 24$ .

Jeffrey Jordon · Accepted Answer

Answer is given below (on video)

To solve: The proportion \frac{5}{3}=\frac{40}{x}.

Answered question

Answer & Explanation

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