I have univariate data (38 is the sample size).The distribution is certainly not normal. How can I find the outliers? I used z-score but am not getting a desired result.
Given some data, my first line of attack is always a plot. A quantile plot shows (ordered) values plotted against cumulative probabilities, or if you like an implicit rank. Here the original data are clearly all positive and collectively positively skewed (left-hand panel), but a logarithmic scale is thereby suggested. When that is tried (right-hand panel), the data look like a very respectable sample from a lognormal distribution, i.e. the logarithms look like a very respectable sample from a normal distribution. Here "very respectable" means very close to the straight line fit which a perfect sample would show.
I see no reason to shout "outlier" here, but every reason to work with a logarithmic transformation or a logarithmic link function.