Asimple random sample is drawn from a normally distributed population, and when making a statistical inference about the population mean, the margin of error is found to be 5.9 at a 95% level of confidence. if the mean of the sample is 18.7, what is the 95% confidence interval for the population mean? a. 18.7 ± 5.9 b. 18.7 ± 9.7 c. 18.7 ± 11.6 d. 18.7 ± 15.2the answer is a

A.

Step-by-step explanation:

The margin of error represents the maximum expected difference between the true parameter and the estimated parameter. It is a way to represent what the uncertainty is with a certain statistic.

Mathematically, confidence interval is

Here, the mean is 18.7 and the margin of error is 5.9, so confidence interval will be,

answer: (-8,4) are the coordinates of a

step-by-step explanation:

let the side of square abcd is x .

thus the area of square abcd is .

now, by the diagram area of triangle ead= 1/2 × ea × ad = 1/2 × ea × x

( because ad is the side of square)

and, according to the question,

the areas of square abcd and right ead are equal.

⇒

⇒ea=2x

thus, ea: ab=2: 1

therefore, point a divides line segment eb into the ratio 2: 1.

⇒ by sectional formula coordinates of a are,

=

=

=(-8, 4)

thus the coordinates of a are (-8,4)