The number of unhealthy days based on the AQI Air Quality In

The number of unhealthy days based on the AQI (Air Quality Index) for a random sample of metropolitan areas is shown. Construct a 95% confidence interval, based on the data.

Solution

Data given is

x	61	12	6	40	27	38	93	5	13	40	335	33.5
x^2	3721	144	36	1600	729	1444	8649	25	169	1600	18117	1811.7
Var(x)	689.45
Std dev	26.25738
z alpha/2	1.96
Margin of error	16.27
Conf interval	(17.27, 49.77)