In 2015 the "Choppergate" controversy embroiled Australian politician Bronwyn Bishop, after she chartered a helicopter to attend a political fundraiser, at taxpayers' expense. In July 2015, Essential Research surveyed a simple random sample consisting of 1,014 Australians aged 18 years or over. Of those surveyed, 25% stated that Bishop should stand down while an investigation into her expenses was undertaken.

(a) The 1,014 people surveyed are a sample. What is the corresponding population?

(b) Is the value 25% a parameter or a statistic? Explain your answer.

(c) For each of the following statements, decide if you think the statement is true or false and give a reason why you think it is true or false.

i. We can use the sample to estimate the proportion of all Australians of any age who want Bronwyn Bishop to stand down while an investigation is undertaken.

ii. We can state that exactly 25% of all Australians aged 18 or over want Bronwyn Bishop to stand down while an investigation is undertaken.