It is to be tested how water resistant the cladding panels of two different manufacturers are. From earlier measurements, it is known that the logarithmic water resistance is approximately normally distributed and that it varies on a similar scale for both manufacturers. The measurements yield

For the level ˛ D 0:01, test whether the water resistance of the cladding panels is the same for both manufacturers.

Manufacturer A 1.845 1.790 2.042 Manufacturer B 1.583 1.627 1.282