Three months ago, santos could walk 2 miles in 40 minutes. today he can walk 2 miles in 25 minutes. what is the percent change?

Jeffery conducted a survey in his school and found that 30 of the 50 eighth grade students' favorite subject is mathematics. based on the results, jeffery concluded that out of the 200 students in his school, 120 students' favorite subject is mathematics. select the statement that is true about jeffery's conclusion. a. jeffery's conclusion is not valid because the sample was biased since only 200 students were surveyed. b. jeffery's conclusion is valid because the sample was random since all of the students were eighth grade students. c. jeffery's conclusion is valid because the sample was random. d. jeffery's conclusion is not valid because the sample was biased since all of the students were eighth grade students.

Suppose you want just guess at the answers in a 5 question multiple-choice test. each question has 3 responses and only one is correct. what is the probability of getting two questions right just guessing? 20 points 0.3275 0.2753 0.7532 none of the above

Consider the proof. given: segment ab is parallel to line de. prove: what is the missing statement in step 5?