In order to estimate the average electric usage per month, a sample of 81 houses was selected and the electric usage was determined. assume a population standard deviation of 450 kilowatt-hours. if the sample mean is 1858 kwh, the 95% confidence interval estimate of the population mean is

The 95% confidence interval estimate of the population mean is (1760, 1956) .

Step-by-step explanation:

Formula for confidence interval for population mean() :

, where n= Sample size

= sample mean.

= Two-tailed critical z-value

= population standard deviation.

By considering the given information, we have

n= 81

kilowatt-hours.

kilowatt-hours.

By using the z-value table ,

The critical values for 95% confidence interval :

Now , the 95% confidence interval estimate of the population mean will be :

Hence, the 95% confidence interval estimate of the population mean is (1760, 1956) .

24

step-by-step explanation:

i assuming that 2 sides are 6 the other 2 sides are 4 cm so 6 times 4 is 24 : )

answer: option a.

step-by-step explanation:

you know that the quadrilateral opqr ( a four sided figure) is inscribed in circle. this means that all its vertices are on the circle.

then, by definition, the opposite angles of the quadrilateral are supplementary, this means that the sum of their measures is 180 degrees.

you can observe in the figure that the angles ∠opq   and the angle ∠orq   are opposite, therefore:

then, can be used to d to calculate the measure of ∠opq