Find the feet to yard ratios for 6 feet

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

The jewelry store is having a sale. necklaces that were regularly priced at $23.50 are on sale for $18.80. what is the percentage of decrease in the price of necklaces?

Ijust need to see how to do this. so you don’t have to answer all of them just a step by step explanation of one.