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 :

except a rational number. : )

3. (5x + 1) - (-10x + 6)

simplify the answer choice. combine like terms. remember to distribute the negative to the terms inside the second parenthesis. also remember that two negatives = one positive, and one of each sign = negative.

- (-10x + 6) = + 10x - 6

simplify. combine like terms:

5x + 1 + 10x - 6

5x + 10x + 1 - 6

15x - 5

∴ it is your answer

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