The discrete random variable $X\,$ has the probability distribution given in the first table below, where $a\,$ and $b\,$ are constants.

$x$	0	1	2	3
$P (X = x)$	0.12	$a$	0.31	$b$

Some cumulative probabilities for $X\,$ are given in the second table below, where $d\,$ and $e\,$ are constants.

$x$	0	1	2	3
$P(X≤x)P(X\le x)$	0.12	0.45	$d$	$e$

Find the value of $a$ .

Find the value of $d$ .

Write down the value of $e$ .

Find the value of $b$ .

The discrete random variable $X\,$ has the probability distribution given in the first table below, where $a\,$ and $b\,$ are constants.

$x$	0	1	2	3
$P (X = x)$	0.12	$a$	0.31	$b$

Some cumulative probabilities for $X\,$ are given in the second table below, where $d\,$ and $e\,$ are constants.

$x$	0	1	2	3
$P(X≤x)P(X\le x)$	0.12	0.45	$d$	$e$

Find the value of $a$ .

Find the value of $d$ .

Write down the value of $e$ .

Find the value of $b$ .

2 Statistics

2 Statistics Questions