Short Answer

In a psychology study with 4040 participants, a score of 2323 has a percentile rank of 8080. If the researcher adds 1010 new participants to the study and all of them score higher than 2323, analyze the effect of this change on the percentile rank of the score of 2323. Support your analysis with the new calculated percentile rank.

Question: In a psychology study with 4040 participants, a score of 2323 has a percentile rank of 8080. If the researcher adds 1010 new participants to the study and all of them score higher than 2323, analyze the effect of this change on the percentile rank of the score of 2323. Support your analysis with the new calculated percentile rank.

Sample answer: Initially, a percentile rank of 8080 in a sample of 4040 means that 3232 scores are lower than 2323. Adding 1010 new participants who all score higher than 2323 increases the total sample size to 5050 while keeping the number of scores lower than 2323 at 3232. The new percentile rank is calculated as (32/50)100=64(32 / 50) * 100 = 64. Therefore, the percentile rank of 2323 decreases from 8080 to 6464.

Key points:

  • Determine that the number of scores lower than 2323 remains 3232.
  • Identify that the total number of scores increases from 4040 to 5050.
  • Calculate the new percentile rank of 6464.
  • Conclude that the percentile rank of 2323 decreases from 8080 to 6464 because of the increased total number of scores.

Rubric: The answer must analyze that the number of scores lower than 2323 remains 3232, while the total sample size increases to 5050. It must calculate the new percentile rank as 6464 and conclude that the percentile rank decreased from 8080 to 6464.

0

1

Updated 2026-05-27

Contributors are:

Who are from:

Tags

KPU

Research Methods in Psychology - 4th American Edition @ KPU

Related