In an experiment: A. one variable is changed to examine its effect.
B. both variable are changed.
C. everything is the same for both the control and the experimental group.
D. there are at least six variable

The arizona department of transportation wishes to survey state residents to determine what proportion of the population would like to increase statewide highway speed to 75 from 65 mph. at least how many residents do they need to survey if they want to be at least 99% confident that the sample proportion is within 0.09 of the true proportion?

Doctors recommend that both men and women take an aspirin every day to prevent heart attacks. however, the sample in the research study only contained men. the problem with doctors making this aspirin recommendation reflects a bias.

Answer asap! what was one main difference between japanese and european feudalism? a)japanese feudalism emerged out of a period of violence; european feudalism did not. b)japanese feudalism was influenced by religions other than christianity. european feudalism involved the exchange of land for services; c)japanese feudalism did not. d)japanese samurai and european knights did not follow similar codes of conduct.