The electric cooperative needs to know the mean household usage of electricity by its non-commercial customers in kwh per day. assume that the population standard deviation is 2.5 kwh. the mean electricity usage per family was found to be 16.5 kwh per day for a sample of 3861 families. construct the 98% confidence interval for the mean usage of electricity. round your answers to one decimal place.

Step-by-step explanation:

Given : Sample size : n= 3861

Significance level :  

Critical value for significance level of :

Sample mean :

Standard deviation :

The formula to find  the confidence interval for population mean is given by :-

i.e

Hence, the 98% confidence interval for the mean usage of electricity :

22

step-by-step explanation:

when rotating a figure 180 degrees, imagine that you are able to take the figure and turn it clockwise or counterclockwise around a center point. to rotate a figure 180 degrees, you will need to apply the rule (x, y) → (-x, -y). start by using a coordinate grid with coordinates for each vertex of the figure. the center point of the coordinate grid is located at (0, 0), which is what you will rotate the figure around. write down the original coordinates of the shape you are going to rotate. then, apply the rule. for example, coordinate (1, 2) becomes (-1, -2). another example would be, coordinate (-4, -2) becoming (4, 2). after you change each original coordinate to the rotated coordinate, you will draw your new figure.

step-by-step explanation: