What to do when encountering this kind of Physics Practical Question?

[ArifKhan]

For example:

It is suggested that the relationship between T and d is

T2(squared)= kd

where k is a constant.

Using your data, calculate two values of k

first value of k

second value of k

and

Justify the number of significant figures that you have given for your values of k.

finally

Explain whether your results support the suggested relationship.

How do you solve this?