When we standardize xbar, we use the formula Z = (xbar-mu) / (sigma/sqrt(n)),
where
xbar = sample mean,
mu = population mean,
sigma = population standard deviation, and
n = sample size
Instead of sigma, if we use the sample standard deviation (s), then it becomes ? = (xbar-mu) / (s/sqrt(n)). What is "?" in the formula above?
a. T
b. C
c. Z
d. F
e. X

For what values of the variable x is the expression square root of 7x+14+ square root of 7-x a real number?

Data from 2005 for various age groups show that for each $100 increase in the median weekly income for whites, the median weekly income of blacks increases by $105. also, for workers of ages 25 to 54 the median weekly income for whites was $676 and for blacks was $527. (a) let w represent the median weekly income for whites and b the median weekly income for blacks, and write the equation of the line that gives b as a linear function of w. b = (b) when the median weekly income for whites is $760, what does the equation in (a) predict for the median weekly income for blacks?

Look at triangle wxy what is the length (in centimeters) of the side wy of the triangle?