[R] Comparing the Means of Two Normal Distributions

[chuck.01]

I haven't put too much thought into this (and this has nothing to do with R),
but...

You have sufficient statistics, and are assuming a normal distribution,
therefore you can "recreate" the two samples using this information. 
Perhaps something like this: 

 N1 <- 100
 N2 <- 130
 x1 <- 30
 x2 <- 33
 s1 <- 1.01
 s2 <- 1.20
 X1 <- rnorm(n=N1, mean=x1, sd=s1)
 X2 <- rnorm(n=N2, mean=x2, sd=s2)

# then do a t.test
t.test(X1, X2)



Lorenzo Isella wrote
> Dear All,
> A problem almost taken from a textbook: I have two independent samples  
> (which are both assumed to come from a normal distribution).
> The sample sizes are N1 and N2, the sample means are x1 and x2 and the  
> sample standard deviations are s1 and s2 (the standard deviations are  
> close).
> I would like to conduct a two sample t-test with equal variances at  
> alpha=0.05 (and then remove the assumption of equal variances).
> I have come across several resources
> 
> http://bit.ly/WKGuHV
> http://bit.ly/WKGwzG
> 
> but the difference here is that I have access only to the N,x and s for  
> the two samples, NOT to the results of every observation (i.e I know for  
> instance N1 x1 and s1, but I do not have the corresponding list of N1  
> values).
> Many thanks for any suggestions.
> Best Regards
> 
> Lorenzo
> 
> ______________________________________________

> R-help@

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> and provide commented, minimal, self-contained, reproducible code.





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