Determine the value of following question

Question- In a population of sea turtles, there is stable census population size of 2000 individuals, but there is a strong sex ratio bias such that females are four-times more common than males.
Meanwhile, in a population of hermaphroditic plants, there is also an average census population size, but with seasonal changes the population alternates back and forth between a size of 1000 and a size of 3000.

Part 1- Calculate the effective population size (Ne) for the turtle population and for the plant population. Show your work and state which of the species exhibits a larger reduction in Ne relative to its census population size [no further explanation required].

Part 2- Briefly explain how both of these examples illustrate the concept of a genetic bottleneck and why, from a genetic perspective, both populations "behave" as though they are smaller than their census size would indicate.

I want help to find the effective population size for the turtle population.