## Steve Ashcroft's computer programmes for Macintosh

### QuickTTest and QuickTTestX

QuickTTest and QuickTtestX are programmes for calculating means, SDs and SEMs and testing the significance of differences using Student's t-test. Their main advantage over other statistical programmes is that data can be input not only as individual values (from the keyboard or by import from a text file) but also as mean ± SD or mean ± SEM for groups. QuickTTest runs on any Macintosh with any system from 7.6 to 9.2 and can be downloaded as a binhex file by clicking here. QuickTTestX runs under Mac OSX and can be downloaded as a disk image by clicking here.

QuickTTestX has been awarded an "EXCELLENT" software certificate by FindMySoft.

### QuickChi and QuickChiX

The chi squared test is one of the most important tests in statistics. It tests whether the observed frequencies in a distribution differ significantly from the frequencies which might be expected according to some 'assumed hypothesis'.

QuickChi and QuickChiX are programmes for carrying out chi squared tests up to a maximum size of 2x5. The programme calculates the value of chi squared and gives you the probability that this value could arise by chance. QuickChi runs on any Macintosh with any system from 7.6 to 9.2 and can be downloaded as a binhex file by clicking here. QuickChiX runs under Mac OSX and can be downloaded as a zipped file by clicking here.You will need Stuffit Expander or similar utility to expand the files.

### CombiStat and CombiStatX

CombiStat and CombiStat are programmes that let you carry out two useful statistical procedures. Firstly, you can combine several Mean±SEM values into an overall Mean±SEM. Secondly, you can calculate the SEM and SD of the ratio (X/Y), product (X*Y), difference (X-Y) and sum (X+Y) of the mean values, X and Y, of two independent variables, x and y, both with an associated SEM. CombiStat runs on any Macintosh with any system from 7.6 to 9.2 and can be downloaded as a binhex file by clicking here. CombiStatX runs under Mac OSX and can be downloaded as a zipped file by clicking here. You will need Stuffit Expander or similar utility to expand the files.