Wednesday 3 November 2021

Benford's Law - From February to the end of June

 In June, I recorded the first digits in the top news article on the BBC website on 24/30 days.  In those 24 articles, there were 353 numbers with leading digits.  That's 14-15 per day, which is a lot more than in March, April and May, but about the same as in February.

2 is appearing the expected percentage of times. 1 and 8 are the most different to their expected values with 1 being over-represented and 8 under-represented. If you add together the sum of all the values of (observed-expected)squared, all divided by the expected, the calculated test statistic is 4.9, the same as May.

The critical chi squared value for 9 items with only one line is ~ 15.507

The test statistic smaller than the critical value therefore the difference is not significant. This data does not disobey Benford's Law.

If we look at the rolling total from February to the end of June, there have been 1599 numbers with leading digits.


2 is exactly its expected value.  1 is the number furthest away from its expected value and remains over-represented, the next furthest away is 6 which is under-represented. If you add together the sum of all the values of (observed-expected) squared, all divided by the expected, the calculated test statistic is 2.71.

The critical chi squared value for 9 items with only one line is ~ 15.507

The test statistic smaller than the critical value therefore the difference is not significant. This data does not disobey Benford’s Law.

This is a reduction from the test statistic of the total to May, but it's not as low as it was before May.

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