any advice?, thanks!
I understand that the reporting of median and quartiles for small samples is an indication of skewed data. If such is correct, then trying to work out the mean and standard deviation given the data below, is useless?
sample N=104; median number per subject (25–75 quartiles): 1.4 (0.0–2.0)
I thought of using the following formulae: sd= sqrt(n) x (upper - lower limit)/ number of standard errors between upper and lower limits
can i assume a normal distribution given that data is based on quartiles?
can I assume that the 25th and 75th quartile are equivalent to the limits of 50% confidence interval (CI)?
once I get the equivalent CIs, I could obtain the number of standard errors in a 50% CI based on a z-score for normal distribution:
se = 0.674 on a one tail and 1.348 on a two tail
so, replacing values on the formulae: sd = sqrt(104) x (0.0 - 2.0)/ 1.348 sd= -15.13
is all the above correct?...
- how could I now obtain the mean?