Question

The following data is arranged to be read down in each column. Each sequential data

It is separated by one year apart.

55,291 66,458 70,237 65,454

59,718 68,548 69,787 64,391

62,688 69,857 68,793 63.62

63,886 70,833 66,388 63,287

Check the assumption of normality in the population. Build a 95% confidence interval for the

average consumption of solar energy.

Answer 1

- Below are data points

Data #	Solar consumption
1	55291
2	59718
3	62688
4	63886
5	66458
6	68548
7	69857
8	70833
9	70237
10	69787
11	68793
12	66388
13	65454
14	64391
15	6362
16	63287

We check the normality plot

From the above normality plot, since p value < 0.05 (alpha = .05) , we reject the null hypothesis and say that data does not follow normal distribution. Above curve also shows that point 15 is an outlier, so we will remove point 15 from data set and will check the normality again.

Here p value = 0.319 > 0.05 (alpha = 0.05), so we accept the null hypothesis and say data follows normal distribution.

95 % CI - Avg consumption of solar energy is 65708 (excluding point 15 because it is an outlier).