(a) (4 points) Write down the four assumptions required to make inferences for a pop- ulation given a sample. (b) (4 points) Propose an unbiased estimator for the average annual income in the county. Show that it's unbiased. (c) (4 points) Find the variance of your proposed estimator. Detail how the variance changes as the sample size increases. Is this change a desirable feature

Nicole purchased a container of cashews that weighs 5 kilograms. zion purchased a container of cashews that weighs 4,900 grams. how many more grams of cashews did nicole purchase?

Grace is standing 18 feet from a lighthouse and kelly is standing 10 feet from grace. the angle that grace looks up to see the top of the lighthouse is 45°. the angle that kelly looks up to see the top of the lighthouse is y°. find the height, h, of the lighthouse. find the angle, rounded to the nearest tenth of a degree, in which kelly looks up to the top of the lighthouse. to the nearest tenth of a degree, find the value of x° . in two or more sentences, explain your calculations

Given: prst square pmkd is a square pr = a, pd = a find the area of pmct.