Question

Difficulty: MediumPercentiles and Quartiles

In a corporate evaluation of 200200 employees, performance scores range from 00 to 100100. An employee with a score of 8484 scored strictly higher than 150150 employees and strictly lower than 4242 employees, while the remaining employees received a score of exactly 8484. If the percentile rank of a score is defined as the percentage of all scores strictly below it plus half the percentage of all scores equal to it, what is the percentile rank of a score of 8484?

  1. A
    75th percentile
  2. 77th percentileAnswer
  3. C
    79th percentile
  4. D
    84th percentile
  5. E
    88th percentile

Answer

77th percentile
The correct answer represents the relative position of a score of 84. Since 150 employees scored lower and 8 employees scored equal to 84, applying the percentile formula yields ((150 + 4) / 200) * 100 = 77th percentile.

Step-by-Step Solution

1
Determine the number of employees scoring exactly 84.
Number of employees scoring 84 = 20015042=8200 - 150 - 42 = 8.
The total group size equals the sum of students scoring below 84, above 84, and equal to 84.
2
Calculate the effective count of scores at or below 84 under the given percentile definition.
Effective count = 150+0.5×8=154150 + 0.5 \times 8 = 154.
The definition specifies adding the count of strictly lower scores to half the count of tied scores.
3
Convert the effective count to a percentile rank.
Percentile rank = 154200×100=77th percentile\frac{154}{200} \times 100 = 77\text{th percentile}.
Dividing by the total number of scores (200200) and multiplying by 100100 converts the count into a percentage.

Key Concept

Percentile Rank Calculation
Estimated Time:1m 30s
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