Stats
posted by Mariaan .
A random sample of 30 women drank an average of 15 cups of coffee per week during examination finals,
with the sample standard deviation equal to 3 cups. A upper limit of an approximate confidence interval
with 95% of the population average cup drunk is ?

95% confidence interval = μ ± 1.96 SE
Standard Error (SE) = SD/√(n1)
Z = (xμ)/SE
1.96 = (x15)/SE
Solve for x.
I hope this helps.