Final answer:
The null hypothesis is that the two types of running shoes have the same durability, and the alternative hypothesis is that they have different durabilities.
Step-by-step explanation:
The null hypothesis in this scenario is H₀: μ₁=μ₂ and the alternative hypothesis is Hₐ: μ₁≠μ₂.
In other words, the null hypothesis states that running shoes 1 and running shoes 2 have the same durability, while the alternative hypothesis states that they have different durabilities.
This is a two-sample hypothesis test comparing the mean durability of the two types of running shoes, and the populations have normal distributions with known standard deviations.