stats question: z test and p value for reaching goal weights?

Question

Group of 45 women with normal distribution have a mean BMI of 29.5 with a standard deviation of 1.6. The goal BMI was 28.5. Did the women meet their goal weight?

After doing the calculations I came up with a Zstat of -4.19 and p value of 0.0000276. While I assume my calculations are correct, how do I interpret this value in relation to the problem?
H0: u=29.5
HA: u=/=29.5

cidyah · Answer

H0: μ = 28.5
Ha: μ ≠ 28.5 ...>goal

Sample mean = 29.5
Standard deviation = 1.6
Standard error of mean = σ / √ n
Standard error of mean = 1.6 / √ 45
SE = 1.6/6.7082
Standard error of mean 0.2385
z = (xbar- μ ) / SE
z = (29.5-28.5) / 0.2385
z = 4.1926

P( |z| > 4.1926) = 0.00
Reject the null hypothesis and conclude the women did not reach their goal.

28.5 is the goal (to be tested)
29.5  is the mean of your sample which could be anything.

stats question: z test and p value for reaching goal weights?

Trending Questions