What is the most significant flaw in this statistical generalisation?

ABC Radio National conducted a phone in poll to find out what Australians think about climate change policy. 90% suggested the government should be doing more to combat climate change. So we can assume around 90% of the country's population agrees.

Question 8

Answer

a.

It involves self-selection.

b.

The methods for collecting data are likely to be unreliable.

c.

There is no flaw.

d.

The population is likely to be heterogenous.