The general way to work this out is to solve the general expression for
the remaining quantity versus half-life, using logarithms. But that's not
necessary with these numbers.
Look at the numbers:
-- 3 mg is 1/4 of 12 mg.
-- 1/4 is the product of (1/2) x (1/2).
-- So the 3 mg is what's left of 12 mg after 2 half-lives.
The 26 minutes must be two half-lives.
-- The half-life of that substance is 26/2 = <em>13 minutes</em>.
Go Maggie !
Answer is From all those aforementioned, the true statement is: Thanh’s grade is 2.5 standard deviations below the mean of the test grades.
explanation
The z scores are standard deviations. If, for example, a tool returns a z score of +2.5, it means that the result is a standard deviation of 2.5. Very high or very low (negative) z scores associated
with very low p values are at the ends of the normal distribution.
If they intersect at a 90 degree angle it’s B. If they never intersect if they continued for ever it’s A. If they intersect but it’s not at a 90 degree angle it’s D.
Answer:
The answer is c because the five is throwing you off
