Question 1168609
mean is 6.58
s=2.35
95% T-half-interval is t(0.975,df=11)*s/sqrt(n)
=2.201*2.35/sqrt(12)
=1.49. Add to and subtract from x bar to get CI limits
(5.1, 8.1). The true mean value is unknown and unknowable, but one can be 95% confident it lies in the interval shown.