William petty's article on harvesting quotes steven covey, who says

William petty's article on harvesting quotes steven covey, who says: the key to being effective in life is "beginning with the end in mind" .

Explanation:

William Petty was a leading British economist. He was the one who proposed various quantitative methods that are still used today to analyze a country's economy. In addition to being a brilliant economist, Petty was a great scientist and son and wrote several articles on various subjects. In her article on the harvest, Petty cited steven covey, another great thinker. The quote said: the key to being effective in life is "beginning with the end in mind"

this null effect is caused by a weak manipulation and ineffective internal validity. in a scientific study, as the one dr. morimoto is trying to perfom, internal validity refers to the confidence placed in the cause-effect relationship and to how well an experiment is done and able to eliminate confounding variables.        

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