According to survey records, 75.4% of women aged 20-24 have never been married. In a random sample of 25 young women aged 20-24, find the mean, variance and standard deviation for the number who are or who have been married.

mean = 6.15

variance = 4.637

standard deviation = 2.15

Step-by-step explanation:

It is given that 75.4% of women aged 20-24 have never been married.

We are interested in finding the mean, variance and standard deviation for the number who are or who have been married.

So the percentile of women who have been married is given by

The mean is given by

Where n is the sample size

Therefore, the mean is 6.15

The variance is given by

Therefore, the variance is 4.637

The standard deviation is given by

Therefore, the standard deviation is 2.15

let's first notice, the center of the hyperbola is at the origin, since the focus points are equidistantly 3 units away from the origin, that also means that the distance "c" from the center to either focus is 3.

it should also be notable that, the traverse axis for this hyperbola is vertical, or namely over the y-axis and therefore, the positive fraction will be the one with y-variable.

the traverse "a" component or distance from the center to either vertex is not 2, is more than 2, so we can safely put it at √5 ≈ 2.24.