1) A study of the effects of caffeine asked volunteers to take a memory test 2 h

Question

1) A study of the effects of caffeine asked volunteers to take a memory test 2 hours after drinking soda. Some drank caffeine-free cola, some drank regular cola (with caffeine), and others dranka mixture of the two (getting half the dose of caffeine). The boxplots to the right are for each group's scores. All are drawn using the same scale. a) What are the best measures for the center and Variable spread for the distribution of scores for those who consumed a high amount of caffeine? Why? (3 points) High Caffeine b) What are the best measures for the center and spread for the distribution of scores for those who consumed no caffeine? Why? (3 points) Low Caffeine Which distribution will have a mean value that is equal to the median value? Why? c) (1 point) No Caffeine d) Which group has the largest median value? (1 point) 15 20 25 30 e) Which group has the largest range of scores? (1 point) f) Which group has the largest interquartile range of scores? (1 point)

Explanation / Answer

SolutionA:

for those who consumed high amount of caffeine mean and standard deviation are the best measures for center and spread for the distribution of scores.

It follows normal distribution

SolutionB:

who consumed no caffeine follows positively skewed distribution.

Median and inter quartile range are the best measures for the center and spread of this distribution.

Median and IQR are best measures as they are not affected by outliers

solutionc:

normal distribution has mean =median

here high caffeine has normal distribution for which mean=median,

From the boxplot the center line which is median cuts the box into two equal halves.

Solutiond:

For low caffeine has the largest median value

median=22.5

Related Questions

Navigate

• Browse (All)
• Browse 1
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.