10.24 For screened coke, the porosity factor is measured by the difference in weight between dry and soaked coke. A certain supply of coke is claimed to have a porosity factor of 1.5 kilograms.

Ten samples are tested, resulting in a mean porosity factor of 1.9 kilograms and a variance of 0.04. Is there sufficient evidence to indicate that the coke is more porous than is claimed? Use and assume the porosity measurements are approximately normally distributed.