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 2.52.5 kWh. The mean electricity usage per family was found to be 1616 kWh per day for a sample of 33943394 families. Construct the 98%98% confidence interval for the mean usage of electricity. Round your answers to one decimal place.

(15.9,16.1) is the required 98% confidence interval for mean usage of electricity.

Step-by-step explanation:

We are given the following in the question:

Sample mean, = 16 kWh

Sample size, n = 3394

Alpha, α = 0.02

Population standard deviation, σ = 2.5 kWh

98% Confidence interval:

Putting the values, we get,

(15.9,16.1) is the required 98% confidence interval for mean usage of electricity.

step-by-step explanation:

you can add the two numbers and divide the result by 2. or you can find the gap between the two numbers and add half of this to the smaller number.

step-by-step explanation :

we know that

the measurement of the outer angle is the semi-difference of the arcs which comprises

in this problem

m< xzy is the outer angle

substitute the values

the measure of angle xoy is equal to

> by central angle

substitute the value