**Tell us what’s happening:**

Hi,

I am very new to freecodecamp and have begun with Data Analysis course. I have looked up in the forum and based on which I have re-written then below code. Each time I run the program there is this error that comes up saying mean is local variable referenced before assignment? Obviously; I can’t submit my Project before this error is resolved. Please assist.

**Your code so far**

import numpy as np

def calculate(list):

```
if len(list) < 9 or len(list) > 9:
print("List must contain only 9 numbers altogether ")
else:
arraylist = np.array(list)
arraylist = arraylist.reshape(3,3)
mean = [(np.mean(arraylist, axis=0).tolist(), np.mean(arraylist, axis =1).tolist(), np.mean(arraylist))]
var = [(np.var(arraylist, axis=0).tolist(), np.var(arraylist, axis =1).tolist(), np.var(arraylist))]
stddev = [(np.std(arraylist, axis=0).tolist(), np.std(arraylist, axis =1).tolist(), np.std(arraylist))]
maxval = [(np.max(arraylist, axis=0).tolist(), np.max(arraylist, axis =1).tolist(), np.max(arraylist))]
minval = [(np.min(arraylist, axis=0).tolist(), np.min(arraylist, axis =1).tolist(), np.min(arraylist))]
sumval = [(np.sum(arraylist, axis=0).tolist(), np.sum(arraylist, axis =1).tolist(), np.sum(arraylist))]
calculations = { 'Mean': mean,
'Variance': var,
'Standard Deviation': stddev,
'Max': maxval,
'Min': minval,
'Sum': sumval
}
return calculations
```

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**Challenge:** Mean-Variance-Standard Deviation Calculator

**Link to the challenge:**