1. Wombats, some species of which are critically endangered, are Australian mammals with a lifespan of up to 15 years in the wild.  In general, wombats in captivity tend to live longer, with the chance of a wombat in captivity living beyond 15 years being 50%.

Scientists in Australia report having found a population of wombats living in a nature reserve that have longer than average lifespans.  In fact, the scientists claim that wombats in the reserve have a greater chance than captive wombats of living beyond 15 years.  A group of naturalists decides to conduct an experiment to test the scientists’ claim. They monitor a random sample of 30 wombats from the reserve and record how long they live for.

State suitable null and alternative hypotheses to test the scientists’ claim.