1. A newspaper article claims that 60% of animal species have become extinct since 1970.  Iggy, a taxonomic biologist, has been studying animal extinction statistics and believes that the proportion is different to the newspaper’s claim.

Iggy collects a random sample of 500 species that were recorded as being in existence in 1970 and records the number that are now extinct.  He uses multiple sources to verify the species’ taxonomic status and finds that the number of extinct species could be as low as 319 or as high as 329.

Iggy wants to use his findings to test his belief, but he also wants to make sure that the test will support his belief for all possible values of the number of extinct species. What is the smallest possible integer percentage value he could use for a significance level to make sure that the test supports his belief?