Abstract
In this study, an experiment related to the breaking hardness of various granular foods is performed using two kinds of hardness testers. The values at the instant when each sample is broken completely are defined as the breaking hardness. The mean, standard deviation, maximum and minimum breaking hardness and its range are evaluated. Furthermore, the histograms of the breaking hardness for all samples are depicted. It is found that those histograms can be expressed approximately as a normal distribution. First, the result is investigated to see whether it could or could not be regarded as a normal distribution using normal probability paper and the X2-test method.
Next, the Weibull probability paper and the X2-test method are applied to see whether it could or could not be regarded as a Weibull distribution. It is clearly shown that the degree of fitness of a normal distribution of the breaking hardness is better than that the Weibull distribution.
