How many subsets of four elements each exist in a set of seven elements?

David must install fencing around a lot that is shaped like a right angle.the side of lot that runs east-west is 200 ft long.the side of the lot runs north-south is 125 ft long.calculate how many feet of fencing he will need to surround the entire lot.

Agame has a rectangular board with an area of 44 in2. there is a square hole near the top of the game board in which you must not toss in a bean bag. the square has side lengths of 3 in. what is the probability of not tossing the bag through the hole? a)9/44 b)3/9 c)3/44 d)35/44

Arandom sample of n = 25 observations is taken from a n(µ, σ ) population. a 95% confidence interval for µ was calculated to be (42.16, 57.84). the researcher feels that this interval is too wide. you want to reduce the interval to a width at most 12 units. a) for a confidence level of 95%, calculate the smallest sample size needed. b) for a sample size fixed at n = 25, calculate the largest confidence level 100(1 − α)% needed.