Question 14tile Choice Worth 5 points) 2
(08.01 MC
A researcher places a radio advertisement offering $32 in exchange for participation in short study. The researcher accepts the first nine people who respond to the advertisement. Which of the following
statements is true about the sample?
It is a valid sample because the first nine people were selected to participate.
It is not a valid sample because it is not a random sample of the population
It is a valid sample because money was offered to participants.
It is not a valid sample because it is only a short study.

Determine whether the set of whole numbers is closed under addition. explain why the set is or is not closed. give an example.

In a test for esp (extrasensory perception), the experimenter looks at cards that are hidden from the subject. each card contains either a star, a circle, a wave, a cross or a square.(five shapes) as the experimenter looks at each of 20 cards in turn, the subject names the shape on the card. when the esp study described above discovers a subject whose performance appears to be better than guessing, the study continues at greater length. the experimenter looks at many cards bearing one of five shapes (star, square, circle, wave, and cross) in an order determined by random numbers. the subject cannot see the experimenter as he looks at each card in turn, in order to avoid any possible nonverbal clues. the answers of a subject who does not have esp should be independent observations, each with probability 1/5 of success. we record 1000 attempts. which of the following assumptions must be met in order to solve this problem? it's reasonable to assume normality 0.8(1000), 0.2(1000)%30 approximately normal 0.8(1000), 0.2(1000)% 10 approximately normal srs it is reasonable to assume the total number of cards is over 10,000 it is reasonable to assume the total number of cards is over 1000

Use the method of cylindrical shells to find the volume v generated by rotating the region bounded by the curves about the given axis. y = 7ex, y = 7e^-x, x = 1; about the y-axis