Question

How many subjects would be needed to ensure that a 95% confidence interval estimate of BMI had a margin of error not exceeding 2 units?

25   27   31   33   26   28   38      41   24 32   35      40

Answer 1

Solution :

Given that,

The following information is provided,

Significance Level,α = 0.05, Margin or Error, E = 2, σ = 5.8827

The critical value for significance level, α = 0.05 is 1.96.

The following formula is used to compute the minimum sample size required to estimate the population mean μ within the required margin of error :

n >= (zc *σ/E)^2
n = (1.96 * 5.8827/2)^2
n = 33.24

Therefore, the sample size needed to satisfy the condition n >= 33.24 and it must be an integer number, we conclude that the minimum required sample size is n = 34

Ans : Sample size, n = 34

NOTE :

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