Help with this bounds question please

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

π = c/ d

We substitute the values to get:

π = 405/130

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.

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

its c or d   take a lucky guess my dude

the square root of what number? if you add that, then someone will probably answer the question.