Short Answer

Assume you have a dataset of four reaction times: 200200 ms, 250250 ms, 280280 ms, and 250250 ms. Apply the formulas for central tendency to calculate the new mean after adding an outlier of 5,000 ms, and explain how this calculation demonstrates the sensitivity of the mean to extreme values.

Question: Assume you have a dataset of four reaction times: 200200 ms, 250250 ms, 280280 ms, and 250250 ms. Apply the formulas for central tendency to calculate the new mean after adding an outlier of 5,000 ms, and explain how this calculation demonstrates the sensitivity of the mean to extreme values.

Sample answer: Adding 5,000 ms to the dataset (200+250+280+250+5000=5980200 + 250 + 280 + 250 + 5000 = 5980; 5980/5=14455980 / 5 = 1445) yields a new mean of 1,445 ms. This demonstrates the mean's sensitivity because a single extreme score pulls the average from 245245 ms to a value higher than 80%80\% of the scores in the dataset.

Key points:

  • The new mean is calculated to be 1,445 ms.
  • The addition of the 5,000 ms outlier pulls the mean drastically from the original 245245 ms.
  • This calculation shows how a single extreme value can prevent the mean from representing typical distribution behavior.

Rubric: Full credit requires: 1. Correctly calculating the new mean as 1,445 ms. 2. Explaining that the extreme outlier pulls the mean up so that it exceeds 80%80\% of the scores, showing its sensitivity.

0

1

Updated 2026-05-27

Contributors are:

Who are from:

Tags

KPU

Research Methods in Psychology - 4th American Edition @ KPU

Related