Answer:
0.689 mg/L Cu
Explanation:
The equation of the best-fit line is:
<em>y</em> = 0.6136<em>x</em> + 0.0142
Where <em>y</em> is the absorbance and <em>x</em> is the concentration in mg/L.
Now using that equation we <u>calculate </u><u><em>x</em></u> when <em>y</em> is equal to 0.438, 0.434 & 0.439.
1) 0.438 = 0.6136<em>x</em> + 0.0142
x = 0.691 mg/L
2) 0.434 = 0.6136<em>x</em> + 0.0142
x = 0.684 mg/L
3) 0.439 = 0.6136<em>x</em> + 0.0142
x = 0.692 mg/L
Finally we <u>calculate the mean of the three concentrations</u>:
- (0.691 + 0.684 + 0.692)/3 = 0.689 mg/L