What Is the Percentile Rank of a 20-Year-Old Machine?

In summary, the conversation discusses finding a percentile ranking for the age of 20 years in a distribution of all ages of inspected machines. The equation provided, (B + 0.5E) / n, is not applicable in this scenario as there are not enough variables given. The only information provided is that 60% of the machines inspected were 20 years or older, leaving 40% that were less than 20 years old. Without knowing the total number of scores, it is not possible to find the percentile ranking.
  • #1
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Homework Statement



60% of all machines inspected were 20 years or older. Give a percentile ranking for the age of 20 years in the distribution of all ages of inspected machines.


Homework Equations



Don't think there are any that apply to this question :/

I found this equation:

Precentile rank = (B + 0.5E) / n

...where B = number of scores below x, E = number of scores equal to x, n = number of scores, and x is the percentile rank you want to find (http://www.regentsprep.org/regents/math/algebra/AD6/quartiles.htm)

But I can't really plug anything in.

The Attempt at a Solution



Maybe this is more on the intuitive side, or I'm not understanding the question. It seems like more variables have to be given, as there isn't much to do!

60% were 20 years or older, so 40% were less than 20. Now what? I'd need to know the total number of scores, wouldn't I?
 
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  • #2
Bump.
 
  • #3
One last bump.

I really need some guiding words!
 

FAQ: What Is the Percentile Rank of a 20-Year-Old Machine?

1. How is percentile ranking determined?

Percentile ranking is determined by comparing an individual's score to the scores of a larger group of individuals who have taken the same test or assessment. The percentile rank represents the percentage of scores that are equal to or lower than the individual's score.

2. What is a good percentile rank?

A good percentile rank depends on the context and purpose of the assessment. In general, a percentile rank above 50 indicates that the individual's score is higher than the majority of scores in the group, while a rank below 50 indicates a lower score.

3. How is a percentile rank different from a percentage?

A percentile rank and a percentage are both ways of representing data, but they have different meanings. A percentage represents a part of a whole, while a percentile rank represents the position of a score within a larger group of scores.

4. Can percentile ranking be used to compare scores from different tests?

No, percentile ranking should not be used to compare scores from different tests. Each test has its own unique scoring system and group of individuals, so percentile ranks cannot be directly compared between tests.

5. How does the concept of percentile ranking relate to standard deviation?

Percentile ranking and standard deviation are both measures of variability in a group of scores. Standard deviation measures the spread of scores around the mean, while percentile ranking compares an individual's score to the entire group of scores. A score that is farther from the mean will have a higher or lower percentile rank, depending on whether it is above or below the mean.

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