David is an engineer from Thailand who has been based in Melbourne, Australia, since 2015. David and his family relocated from Thailand to Australia in 2015 with the goal of settling down there permanently. He bought a home in Melbourne and enrolled his children in a nearby primary school. David and his wife have a joint bank account in Thailand, however, the year he arrived in Australia, he opened a joint account. David has also invested in a Thailand business after moving to Australia. David began a three-year project off the coast of the USA in July 2020. David was recruited for this role because of his engineering expertise, and the contract was signed in Australia before he left. His earnings from his US job are deposited into a joint Australian bank account. David's family has been travelling overseas rather than returning to Australia since he began his US job, in order to see him on a regular basis. The family gathers in different parts of the world, though it is frequently in Thailand, where his extended family lives. David has only been to Australia once, during one of his scheduled vacation weeks. Q1) Answer to the following questions to determine if David is a tax resident of Australia for the 2020-2021 tax year. In your study, make sure to cite applicable laws, case law, and tax rulings. There are no calculations required. Q2) Analyze David's situation in light of section 6(1) ITAA36's "resides exam." Q3) Examine David's situation in light of section 6(1) ITAA36's "domicile test." Q4) Given that the superannuation test and the 183-day test are unlikely to apply to David's situation, what is your ultimate conclusion on whether David is a tax resident of Australia, and what are the implications of this determination