A doctor wants to estimate the HLD cholestorol of all 20-to-29-year-old females.

Question

A doctor wants to estimate the HLD cholestorol of all 20-to-29-year-old females. How many subjects are needed to estimate the HDL cholesterol within 3 points with 99% confidence assuming standard deviation=16.5? suppose the doctor would be content with 95% confidence. How does the decrease in confidence affect the sample size required?

A 99% confidence level requires ________ subjects.

A 95% confidence level requires ________ subjectt.

How does the decrease in confidence affect the sample size required?

Explanation / Answer

For 99 % confidence, z = 2.575

Standard error = z* Standard deviation/Sqrt(n)

or, 3 = 2.575 *16.5/sqrt(n) which gives n as 200.57

N = 201(Rounding up)

For 95 % confidence, 3 = 1.96*16.5/sqrt(n) which gives n as 116.24 or 117

Decrease in confidence decreases the sample size required.

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.