A new treatment in the form of tablets for the prophylaxis of migraine has been introduced, to be taken before an impending attack.

A doctor carried out a pilot study with this preparation on 8 patients, giving a placebo to 10 other patients. The numbers of migraine attacks experienced by the patients over a period of 6 months were as follows.

Group receiving new preparation:

patient (#1) 8; (#2) 6; (#3) 0; (#4) 3; (#5) 14; (#6) 5; (#7) 11; (#8) 2

Group receiving placebo:

patient (#9) 7; (#10) 10; (#11) 4; (#12) 11; (#13) 2; (#14) 8; (#15) 8; (#16) 6; (#17)1; (#18) 5.

Is the difference significant at the 5% level?