When conducting a survey, it is important to use a random sample:to get a significant result. to avoid bias and to get a representative sample. so that we can make causal conclusions. to ensure truthful answers to the survey's questions. none of the above.

to avoid bias and to get a representative sample

Step-by-step explanation:

A random sample is useful for:

Avoid bias: if you have a selected sample, all of the selected individuals may have some common factor (same age group, same salary rage, same political ideology) so the sample may be kinda biased, this is something that you may want to avoid.

All the other options can not be ensured by any method, you survey, even with a random sample, may have no significant result, and you can not ensure that the surveyed people will answer truthfully.

sinn is the total amount of students now and m were the students before, you subtract them both (n-m) and divide that by m. then, since to get a percentage from a fraction you have to multiply by 100, your answer should look like this: n-m/m*100

step-by-step explanation: