Suppose that a researcher is interested in estimating the mean systolic blood pressure, , of executives of major corporations. He plans to use the blood pressures of a random sample of executives of major corporations to estimate . Assuming that the standard deviation of the population of systolic blood pressures of executives of major corporations is mm Hg, what is the minimum sample size needed for the researcher to be confident that his estimate is within mm Hg of

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yogeshkumar49685 yogeshkumar49685 · Answer 1 · 2022-07-16T04:42:58+02:00

The minimum sample size needed in the research of systolic blood pressure is 68.

Given standard deviation=25 mm Hg, confidence level=90%, Estimation =5 mm Hg.

We have to first find the level of alpha which is known as error.

α=(1-0.9)/2

=0.05

Now we have to find z in the z table as such z has a p value of 1-α,that is z with a p value of 1-0.05

=0.95 ,so Z=1.645.

now finding the margin of error, which is as under:

[tex]M=z st/\sqrt{n}[/tex]

in which st is standard deviation and the n is sample size of population.

By assuming the standard deviation of 25 mm Hg we get values as under:

n is sample size.

[tex]M=z* st/\sqrt{n}[/tex]

[tex]5=1.645*25/\sqrt{n}[/tex]

[tex]5\sqrt{n}=1.645*25\\[/tex]

dividing both sides by 5

[tex]\sqrt{n}=1.645*5[/tex]

squaring both sides we get

n=67.65.

Hence the sample size needed by the researcher is 68.

Learn more about margin of error at https://brainly.com/question/24289590

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The given question is incomplete as it should includes :

standard deviation= 25mm Hg

Confidence level=90%

Estimation 5 mm Hg of u.