Why is a randomized, blinded experimental study best for establishing cause-effect relationships?
a. randomization balances out the effect of confounding factors
b. this study design establishes a time sequence of events
c. blinding can minimize bias
d. all of the above are reasons
why this is the preferred study design?

The chart shows the marginal cost and marginal revenue of producing apple pies. what most likely will happen if the pie maker continues to make additional pies? the marginal costs will continue to rise, increasing the total cost, while the marginal revenue remains the same, decreasing the profit. the marginal costs will continue to fall, decreasing the total cost, while the marginal revenue remains the same, increasing the profit. the marginal costs will continue to rise, increasing the total cost, while the marginal revenue remains the same, increasing the profit. the marginal costs will continue to fall, decreasing the total cost, while the marginal revenue remains the same, decreasing the profit.

Tanya was used to using word, and she did some work for her brother mike, who was using wordperfect. tanya was quickly able to use wordperfect for windows with little difficulty, since many of the commands for it were the same as the commands for word. tanya's ability to use wordperfect best illustrates:

The provisions of subpart d, of the hhs regulations, additional protections for children involved as subjects in research apply to: all research involving childrenall research that is > minimal riskall research funded by any federal agencyall research funded by hhs