Question

For a biology lab experiment, you have to randomly select four mice. The mice to be chosen come from a population bred to weigh 30 grams, give or take 5 grams or so. The total weight T of the four mice will be___________ grams, give or take__________ grams or so. Use the Pythagorean property of standard errors.

Answer 1

Answer:

120; 10

Step-by-step explanation:

The total weight T of the four mice is simply the sum of each individual weight, assuming the mean value as true:

$T=30+30+30+30 = 120\ grams$

Pythagorean property of standard errors assumes that:

$SD^2(X)+SD^2(Y)=SD^2(X\pm Y)$

Therefore, the standard error of the total weight is:

$SD(T) = \sqrt{5^2+5^2+5^2+5^2}\\ SD(T) = 10\ grams$

The total weight T of the four mice will be 120 grams, give or take 10 grams or so.