Read the environmental brief below.
Kakadu National Park in Australia’s Northern Territory is a major biodiverse reserve. Annually, the park's conservation program monitors the seasonal dynamics of its avian populations. During the wet season, the park hosts approximately 4.5 million4.5\text{ million}4.5 million migratory waterfowl. In contrast, the resident avian population during the dry season is estimated at 750,000750,000750,000. Additionally, the park receives over 250,000 250,000\,250,000 human tourists annually, requiring careful ecological management.
Express the ratio of the resident avian population to the migratory waterfowl at Kakadu National Park in its simplest form.
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