Darrin is a good pianist. however, when he is alone, he becomes lethargic and is not motivated to perform well. at recitals with strangers, darrin gets very overly aroused and often makes mistakes. his best performance is typically when his family and friends are nearby. in such situations, darrin isn’t nervous and is only moderately aroused. this scenario best exemplifies the principle of

Yerkes-Dodson law.

Explanation:

The Yerkes – Dodson Law was originally proposed by Robert Yerkes and John Dillingham Dodson in 1908.

They discovered a direct relationship between performance and arousal. Up to a certain point, performance improves with physiological arousal, because it boosts concentration and motivation, but when arousal becomes too much, performance levels go down.

u.s. presidents buried at arlington national cemetery include john f. kennedy and william howard taft. the kennedy gravesite is the final resting place not only of the former president, but also his wife jackie kennedy, his two brothers robert and edward kennedy, as well as a memorial to his brother joe jr.good luck

explanation:

answer; i believe the correct answer is (4) flip a coin as each participant arrives,heads indicates assignment to the first group: tails indicates assignment to the second group;