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| In R the percentage of people with a score equal or below 3 can be written as | In R the percentages of people with scores equal or below each observed score can be obtained by running |
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| 100*sum(score<=3)/length(score) | > for (i in score) { + perc[i] <- 100*sum(score<=i)/length(score) + } > perc |
How do I find out how many people have a score above a certain value?
Percentiles give the percentage of people who have a score below a threshold score.
Percentile (score) = 100 $$\frac{\mbox{n} \leq \mbox{score}}{\mbox{N}}$$
1 - Percentile (score) = 100 $$\frac{\mbox{n} \gt \mbox{score}}{\mbox{N}}$$
The percentiles for each score are routinely outputted using the frequency procedure in SPSS.
FREQUENCIES VAR=SCORE. EXE.
In R the percentages of people with scores equal or below each observed score can be obtained by running
> for (i in score) {
+ perc[i] <- 100*sum(score<=i)/length(score)
+ }
> perc