We say that a point estimator is unbiased if (choose one): its sampling distribution is centered exactly at the parameter it estimates. the standard deviation of its sampling distribution decreases as the sample size increases. its sampling distribution is normal. its value is always equal to the parameter it estimates. choices (a), (b), and (c) are all true.

The height of a triangle is 4 in. greater than twice its base. the area of the triangle is no more than 168 in.^2. which inequalitycan be used to find the possible lengths, x, of the base of the triangle?

Mr and mrs smith buy tickets for themselves and their four children. the cost of an adult ticket is ? 6 more than the adult ticket. the total cost of the six tickets is ? 40.50 work out the cost of an adult ticket. in your working let c be the cost of the child ticket and a be the cost of the adult ticket.

The box plot shows the number of raisins found in sample boxes from brand c and from brand d. each box weighs the same. what could you infer by comparing the range of the data for each brand? a) a box of raisins from either brand has about 28 raisins. b) the number of raisins in boxes from brand c varies more than boxes from brand d. c) the number of raisins in boxes from brand d varies more than boxes from brand c. d) the number of raisins in boxes from either brand varies about the same.