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Results tagged with mean
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user 73691
The expected value of a random variable; or a location measure for a sample.
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vote
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answer
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Is this a valid way to calculate an SD of a pooled sample (NOT a pooled SD)?
Obviously you can calculate a pooled SD (NOT what I want) it in R with something like this:
n <- c(35,40)
mean <- c(22.3,28.0)
sd <- c(3.2, 4.9)
df <- data.frame(n,mean,sd)
sqrt( sum(df$sd^2 * (df$n … )))
+ }
> mean(result)
[1] 5.06259
I iterated 10000 times to get a good average. …
- 473