What is the coeffieent of (x^4)(y^4) in the expansion of (x+y)^8

The table below shows the height of a ball  x  seconds after being kicked.  what values, rounded to the nearest whole number, complete the quadratic regression equation that models the data? f(x)  =  x2  +  x  +  0based on the regression equation and rounded to the nearest whole number, what is the estimated height after 0.25 seconds?   feet

Select the margin of error that corresponds to the sample mean that corresponds to each population: a population mean of 25, a standard deviation of 2.5, and margin of error of 5%

Given sin28.4=.4756, cos28.4=.8796, and tan28.4=.5407 find the cot of 61.6