Question

We heard that there was a 90% confidence interval for the population mean from 22.5 to 2am 8.3, determine the point estimate of the population and the margin of error associated with the information.

Answer 1

$$Confidence\ interval\ width$$

$$=2\times margin\ of\ error$$

$$margin\ of\ error=\dfrac{28.3-22.5}{2}=2.9$$

$$\bar{x}=22.5+2.9=25.4$$

The sample mean $\bar{x}=25.4$ is a point estimate of the population mean.

The margin of error is $2.9.$