https://www.webassign.net/clstatsup1/sip/videos/hand_washing.mp4

Stats in Practice: Elementary Probability Theory

• Part I - Multiple Choice QuestionsThe video indicates which of the following is an acceptable alternative to washing your hands for 20 seconds with respect to preventing illness?

A. getting a flu shot,

B. rinsing with mouthwash that has at least 15% alcohol,

C. washing your hands for 10 seconds with water that exceeds 100 degrees Fahrenheit,

D. using hand sanitizer with at least 60% alcohol

• The video urges people to wash their hands to reduce the likelihood (that is, the probability) of contracting diseases. What does this imply?

A. If you don't wash your hands, you will contract a disease. That is: P(contracting a disease if you don't wash your hands) = 1.,

B. If you contracted a disease, you must have not washed your hands. That is: P(washed your hands if you contracted a disease) = 0.,

C. The probability of contracting a disease is lower if you wash your hands than if you don't wash your hands. That is: P(disease if you wash your hands) < P(disease if you don't wash your hands).,

D. If you wash your hands, you will not contract a disease. That is: P(contracting a disease if you wash your hands) = 0.

• Suppose a student has had one illness in the last month, but her roommate has had two. With no other information about this student or her roommate, given the information in this video, what is your best guess about the student's and her roommate's hand-washing habits?

A. The student does the best job of washing her hands., or

B. The student's roommate does the best job of washing her hands.

• Suppose you have already had a disease, D, and doctors tell you that you cannot contract it again. Assuming the doctors are correct, which of the following probability statements about your contracting the disease is correct, where

P(D) stands for "the probability of contracting the disease"? (Hint: A probability is a value between 0 and 1, where 0 means that the event will not occur with certainty and 1 means the event will occur, with certainty.)?

A. 0 < P(D) < 1

B. P(D) = 0.5

C. P(D) = 0

D. P(D) = 1