Question 1120543
Point estimate is the results 290/340 or 0.8529
99% CI ls mean +/- z0.995* sqrt (p*(1-p)/n)
The interval is 2.576*sqrt(0.8529*0.1471/340); sqrt term is 0.0192
The CI is 0.8529-0.0495, 0.8529+0.0495 or (0.8034, 0.9024)
We don't know the true proportion of customers, but we are extremely confident it lies in the above interval.