Question

Helen draws a random circle.

Answer 1

Answer:

Upper bound 3.116

Lower bound 3.125

Step-by-step explanation:

The random circle Hellen drew has a circumference of C=405mm to 3 significant figures and she gets a diameter, d, of 130 mm correct to 2 significant figures.

We need to use the formula

$\pi = \frac{C}{d}$

We substitute the values to get:

$\pi = \frac{405}{130}$

$\pi = 3.11538461538$

Therefore Hellen's value for π is 3.115 to three decimal place.

To find the lower and upper bound, we half the specified degree of accuracy.

$\frac{0.001}{2} = 0.0005$

We then add it to the rounded value to get the upper bound to be:

3.115+0.0005=3.1155

The lower bound is 3.115-0.0005=3.1145