# CHITEST gives unexpected value

I have two columns denoting respectively **observed and expected frequency**, I then calculate **X²** (chi-square) for each row with `((OBSERVED-EXPECTED)^2)/EXPECTED)`

and proceed to `SUM`

all rows to get the actual **X²** value. The resulting value is different from the value given by `CHITEST`

and I can't seem to understand why (in fact, I can't really find much documentation about this function at all).
Also, the values in my table are rounded for display.

```
Observed Expected X²
3 4.0 0.26
15 18.5 0.66
47 42.5 0.47
76 65.2 1.78
68 75.0 0.66
74 69.0 0.36
46 52.9 0.90
39 34.8 0.52
15 20.0 1.25
9 10.2 0.15
5 4.7 0.02
2 2.0 0.00
0 0.8 0.75
1 0.3 2.02
SUM: 9.782 CHITEST: 0.712
```

Here's my table (in case it's useful): Exemplo_Qui-Quadrado.ods

Could someone explain to me how is the value of `CHITEST`

calculated?