, 30.06.2019 11:30 pr47723

# Abox contains 18 balls numbered 1 through 18. two balls are drawn in succession without replacement. if the second ball has the number 4 on it, what is the probability that the first ball had a smaller number on it? an even number on it?

### Another question on Mathematics

Mathematics, 21.06.2019 15:00
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.