If by decreasing the positive value of a variable $x$ or by increasing negatie value of the variable $x$;
the value of $x$ is brought very close to $' 0 '$ then it can be said that $x$ tends to $0 .$
It is denoted by $x \rightarrow 0$.
Here, $x \rightarrow 0$ means the value of $x$ approaches very close to $0$ but it will not be equal to $0 .$
For a normal distribution, the estimated value of quartile deviation is $12 .$ Find the value of its standard deviation.
Answer
In normal distribution fourth quartile $=\frac{2}{3} \sigma,$
therefore $12=\frac{2}{3} \sigma$
$\therefore \sigma=\frac{12 x^3}{2} 18 \text {. }$
Thus, the value of sturdard deviation is $18 .$
State the formula for the probability of occurrence of atleast one event out of three events $A , B$ and $C$.
Answer
Occurrence at least one event out of three evens $A , B$ and $C$ or $A B C$.
$P ( A \cup B \cup C )= P ( A )+ P ( B )+ P ( C )- P ( A \cap B )- P (\cap C )- P ( B \cap C )$$+ P ( A \cap B \cap C )$
The co-efficient of $b$ of $x$ in the linear regression model is known as coefficient of regression. OR The approximate change in the value of dependent variable for $a$ unit change in the value of independent variable. $b$ represents the appropriate increase or decrease in the value of $Y$ per one unit increase or decrease in the yalue of $X$.