The use of the internet is constantly growing. How many randomly selected adults must be surveyed to estimate the percentage of adults in the United States who now use the internet? Assume we want to be 99% confident that the sample percentage is within 2 percentage points of the true population percentage. a) Assume that nothing is known about the percentage of adults using the internet.

b) Assume it was estimated that 72% of adults in the United States use the internet.

Aresearch study is studying the effects of a new drug for osteoporosis alzheimer's disease (ad) for women above the age of 65 years. a group of individuals with osteoporosis is randomized into two groups. one group is treated conventionally, and the second group is treated with the new medication. assessments are made at 3, 6, 12, 36, and 48 months. the conventionally treated group is assessed for ad using a serum blood test, and the treatment group is assessed for ad using a pet radiotracer that binds to beta-amyloid plaques. in comparing these 2 trial arms, the authors of the study may encounter which type of bias? a. selection bias on the risk of developing b. measurement bias c. confounding bias d. recall bias e. lead-time bias