12. In a study of visual perception, five people were asked to estimate the leng

Question

12. In a study of visual perception, five people were asked to estimate the length of a line by eye and then to mea- sure it with a ruler. The results, in cm, were: By eye: 8.0, 9.0, 7.5,9.5, 8.5 With a ruler: 8.1, 8.2, 8.1, 8.1, 8.3 a. Compute the mean measurement for each method. b. Compute the median measurement for each method. c. Compute the standard deviation of the measure- ments for each method. d. For which method is the standard deviation the largest? Why should one expect this method to have the largest standard deviation?

Explanation / Answer

a) b) and c)

d)

Standard Deviation is largest in the method in which measurements reported by eye

With eye, the margin for error is more as it is a physical attribute

Ruler, on the other hand, is calibrated and so margin for error is less

e)

It is better to have a smaller Standard Deviation as it shows that the observations made are close and has low outliers. The data points are more clustered in samples with low Standard Deviation

By Eye By Ruler 8 8.1 9 8.2 7.5 8.1 9.5 8.1 8.5 8.3 Mean 8.5 8.16 Median 8.5 8.1 Std Dev 0.79 0.09

Related Questions

Navigate

• Browse (All)
• Browse 1
• Subjects

---

---

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