Answer: a) 56, b) because there is a bias towards girls, where there are more girls in the sample than boys
Explanation:
a) We know that sample contains 40% of the students who play sports, we also know that there are 139 girls who play sports, therefore to predict how much girls are in the sample we can just do 139×0.4, we multiply it by 0.4 because 40% is 40/100 which is 0.4. Anyhow, the answer would be 55.6, and the question tells us to round to the nearest integer which would be 56
b) as we all know 70 is way more than 56, if there is 70 girls in the sample, that means that there are less boys than there should be, such situation would result in bias towards girls which would result in inaccuracies in some decisions that contains public opinion, if you want to make sample without bias, it should be most random and evenly distributed.
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