Letter: The wettest day of the week put to the test

Sir: It may seem impertinent for a simple graduate to criticise his betters, but surely Professor MacDonald Jackson has used the wrong statistical test in his letter (27 July). The chi-square test is used to test frequencies of occurrence. In this case we have interval data and should use a 't' test, requiring a knowledge of the standard deviations of the sets of data. Notwithstanding this, the result will probably be similar.

In my view, Thursday is the wettest day as it is the first day of a Test match. The selectors use this information to pick four seamers who then prove woefully inadequate for the remaining four dry days.

Yours faithfully,

ALAN FARR

British Sky Broadcasting

Southampton

27 July