<span>A medical researcher wants to investigate the amount of time it takes for patients' headache pain to be relieved after taking a new prescription painkiller. She plans to use statistical methods to estimate the mean of the population of relief times. She believes that the population is normally distributed with a standard deviation of 18 minutes. How large a sample should she take to estimate the mean time to within 4 minutes with 97% confidence?
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n = [z*s/E]^2
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n = [2.17*18/4]^2 = 96 when rounded up
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30 + (40 × 3) = 150
60 + (30 × 3) = 150
in three months the total cost would he the same.
Your answer will be 17/15
Firstly you should use Pythagorean’s theorem like this
H²=p²+b²
Where p is bc
And b is ac
Then keep the value and solve it and you will get h as 17
At last keep cosA = b/ h
Hope it helps : )
If you didn’t understand please tell me
