DMR #1

• Have you ever been walking through the mall and someone asked you if you would take a survey for them? When the results of a survey like this are released, can we apply them to the entire population? Why or why not?

DMR #2

DMR #3

DMR #4• Identify the type of bias involved and state

whether you think the sample proportion obtained is higher or lower than the true population proportion.

DMR #5• Vitamin E may have special health benefits.• Large doses of vitamin E apparently can reduce harmful side effects of

bypass surgery in heart patients. A study involving 28 bypass patients found that the 14 randomly-assigned patients who took vitamin E for two weeks before their operations had significantly better heart function after the procedure than the 14 randomly-assigned patients who took placebos. The vitamins apparently prevent damage to the heart muscle by destroying the toxic chemicals, called free radicals, that form when blood is cut off during the surgery, said Dr. Terrance Yau of the University of Toronto.

• Explain why this is an experiment and not an observational study.

• Identify the explanatory and response variables.

DMR #6

DMR #7• Vitamin E may have special health benefits.• Large doses of vitamin E apparently can reduce harmful side effects of

bypass surgery in heart patients. A study involving 28 bypass patients found that the 14 randomly-assigned patients who took vitamin E for two weeks before their operations had significantly better heart function after the procedure than the 14 randomly-assigned patients who took placebos. The vitamins apparently prevent damage to the heart muscle by destroying the toxic chemicals, called free radicals, that form when blood is cut off during the surgery, said Dr. Terrance Yau of the University of Toronto.

• In the second sentence above is the phrase, “…the 14 patients who took vitamin E for two weeks before their operations had significantly better heart function after the procedure …” What is the statistical meaning of the word “significantly” in the context of this study?

DMR #8

DMR #9

DMR #10

DMR #11

DMR #12

DMR #13