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The sides of triangles were measured and recorded as 8.4 cm, 10.5 cm and 15.3 cm. Calculate the percentage error in perimeter

The sides of triangles were measured and recorded as 8.4 cm, 10.5 cm and 15.3 cm. Calculate the percentage error in perimeter correct to 2 decimal places

Answers

Absolute error in the

measurements

8.4 = $\frac{0.1}{2}$ = 0.05

10.5 = $\frac{0.1}{2}$ = 0.05

15.3 = $\frac{0.1}{2}$ = 0.05

Actual perimeter

= 8.4 + 10.5 + 15.3

= 34.2 cm

Maximum perimeter

= 8.4 + 10.55 + 15.35

= 34.35 cm

minimum perimeter

= 8.35 + 10.45 + 15.25

= 34.05

Absolute error in perimeters

[Max Perimeter - Minimum Perimeter] +
$\frac{Actual\;Perimeter - Minimum\;Perimeter}{2}$

= $\frac{[34.35 \;- \;34.2][34.2 - 34.05]}{2}$

= $\frac{0.15\;+\;0.15}{2}$ = 0.15

% error in the perimeter

$\frac{0.15}{34.2}$ x 100 = 0.44%

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johnmulu answered the question on March 7, 2017 at 13:57

Next: The equation of a curve is y = 3x² -4x + 1, Find the gradient function of the curve and its value when x = 2
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