The solution of the proportion \frac{3}{8}=\frac{b}{10}.

Concept used:
To get rid of a number in addition from one side, subtract the same number from both sides of equal sign.
To get rid of a number in subtraction from one side, add the same number both sides of equal sign.
To get rid of a number in multiplication from one side, divide the same number from both sides of equal sign.
To get rid of a number in division from one side, multiply the same number both sides of equal sign.
Rules of Addition/ Subtraction:
Two number with similar sign always get added and the resulting number will carry the similar sign.
Two numbers with opposite signs always get subtracted and the resulting number will carry the sign of larger number.
Rules of Multiplication/ Division:
The product/quotient of two similar sign numbers is always positive.
The product/quotient of two numbers with opposite signs is always negative.
Calculation:
In order to solve the given equation ${\displaystyle \frac{3}{8}=\frac{b}{10}}$ for the variable, isolate the variable term p on one side by performing some basic algebraic operations to get rid of the other numbers and terms associated with it.
Here to isolate p on both side, first multiply both sides by u and then multiply both sides by 10 and then simplify further as shown below,
${\displaystyle \frac{3}{8}=\frac{b}{10}}$
${\displaystyle \frac{3}{8}\cdot 10=\frac{b}{10}\cdot 10}$
${\displaystyle \frac{30}{8}=b}$
${\displaystyle \Rightarrow b=3.75}$
Thus, the solution of the proportion is ${\displaystyle b=3.75}$.