Q:

The amounts (in ounces) of juice in eight randomly selected juice bottles are: 15.8, 15.6, 15.1, 15.2, 15.1, 15.5, 15.9, 15.5 construct a 95% confidence interval for the mean amount of juice in all such bottles. assume an approximate normal distribution.a.(15.250, 15.675)b.(15.206, 15.719)c.(15.257, 15.668)d.(15.284, 15.641)e.none of the above

Accepted Solution

A:
The confidence interval is given by the formula:
m +/- z·(σ/√n)

First, compute the mean:
m = (15.8 + 15.6 + 15.1 + 15.2 + 15.1 + 15.5 + 15.9 + 15.5) / 8
    = 15.463

Then, compute the standard deviation:
σ = √[∑(v - m)²/n]
   = 0.287

The z-score for a 95% confidence interval is z = 1.96.

Now you can calculate:
m + z·(σ/√n) = 15.463 + 1.96·(0.287/√8)
                        = 15.463 + 0.199
                        = 15.662

m - z·(σ/√n) = 15.463 - 1.96·(0.287/√8)
                        = 15.463 - 0.199
                        = 15.264

Therefore the confidence interval is (15.264, 15.662) and the correct answer is E) none of the above.