What type of sample would be representative of a whole group? biased sample random sample any sample free sample

Mustafa contributes 11% of his $67,200 annual salary to his 401k plan. what is his pretax income

Twice the sum of a number and 4 is equal to three times the difference of the number and 7. find the number.

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?