The following comment in the code gives a hint that it does not represent the central moment. It seems to be keeping tracking of moment about the origin (as opposed to moment about the mean.)

I found that OnlineStats provides `skewness`

and `kurtosis`

functions that take `Moments`

as an argument, hence:

```
julia> ws.stats
(Mean(0.00491932), Variance(0.995698), Moments([0.00491932, 0.995622, 0.0196614, 2.99593]))
julia> skewness(ws.stats[3])
0.004999061081258352
julia> kurtosis(ws.stats[3])
0.02163099361000098
```

and the kurtosis matches the type-3 value from R.

```
> skewness(x, type=3)
[1] 0.00500054
> kurtosis(x, type=3)
[1] 0.02163099
```

Skewness is still a little off. Following Wikipedia’s conversion formula:

\mu _{3}=\mu '_{3}-3\mu \mu '_{2}+2\mu ^{3}

I can now match skewness exactly:

```
julia> function myskewness(o::Moments)
v = value(o)
(v[3] - 3.0 * v[1] * v[2] + 2 * v[1] ^ 3) / var(o) ^ 1.5
end
myskewness (generic function with 1 method)
julia> myskewness(ws.stats[3])
0.005000540061498055
```

So it looks like it’s just an issue with with OnlineStats…