When determining the sample size required for a 95% confidence interval for the population mean, the sample mean needs to be known. a. True b. False

True

Step-by-step explanation:

When dealing with confidence intervals for the population mean, the formula is;

x¯ - z_α(σ/√n) ≤ μ ≤ x¯ + z_α(σ/√n)

Where;

μ is population mean

x¯ is sample mean

z_α is z-value of confidence interval

σ is population standard deviation.

n is sample size

From the formula, we can see that when we rearrange it to make the sample size the subject, it is clear that we need to know the value of the sample mean x¯ in order for us to solve for the sample size

ruth is 6 years old

step-by-step explanation:

6 + 24 = 30,   so 6/30 = .2  

if you do 1/5 it also equals .2, so that is the answer.

step-by-step explanation: