First, find the mean. You'll need it to compute the variance.
The variance of the sample is then computed with the formula
The standard deviation is the square root of the variance, so
That’s all correct thanks
1) you add the variables in the bracket
(4+5)÷3×4
9÷3×4
2) you multiply 3 by 4
9÷3×4
9÷12
3) now you divide 9 by 12
9÷12
=0.75
Step-by-step explanation:
Use the quadratic formula
=
−
±
2
−
4
√
2
x=\frac{-{\color{#e8710a}{b}} \pm \sqrt{{\color{#e8710a}{b}}^{2}-4{\color{#c92786}{a}}{\color{#129eaf}{c}}}}{2{\color{#c92786}{a}}}
x=2a−b±b2−4ac
Once in standard form, identify a, b and c from the original equation and plug them into the quadratic formula.
2
2
+
6
+
4
=
0
2x^{2}+6x+4=0
2x2+6x+4=0
=
2
a={\color{#c92786}{2}}
a=2
=
6
b={\color{#e8710a}{6}}
b=6
=
4
c={\color{#129eaf}{4}}
c=4
=
−
6
±
6
2
−
4
⋅
2
⋅
4
√
2
⋅
2
x=\frac{-{\color{#e8710a}{6}} \pm \sqrt{{\color{#e8710a}{6}}^{2}-4 \cdot {\color{#c92786}{2}} \cdot {\color{#129eaf}{4}}}}{2 \cdot {\color{#c92786}{2}}}
x=2⋅2−6±62−4⋅2⋅4
brainliest and follow and thanks
