scores on an aptitude test are distributed with a mean of 220 and a standard deviation of 30. the shape of the distribution is unspecified. what is the probability that the sampling error made in estimating the population mean of a random sample of 50 test scores will be at most 5 points

Find the value of the cosine for angle a

Kayla wants to find the width, ab, of a river. she walks along the edge of the river 65 ft and marks point c. then she walks 25 ft further and marks point d. she turns 90° and walks until her location, point a, and point c are collinear. she marks point e at this location, as shown. (a) can kayla conclude that δ and δ are similar? why or why not? (b) suppose de = 15 ft. what can kayla conclude about the width of the river?

Daniel expanded the expression as shown below -2(-8x-4y+3/4)=-10x-8y-11/4 what errors did he make? check all that apply