A large polling agency polls 1600 adult South Africans at random and the results are shown in the table on the right.

Find a 95% CI on the true proportion of South Africans that make more than R600,000 a year.

2013 Year end Salary	Number
less than R300,000	480
between R300,000 and R600,000	800
between R600,000 and R900,000	224
between R900,000 and R1,200,000	64
more than R1,200,000	32

	a.	[0.28,0.32]
	b.	[0.18,0.12]
	c.	[0.18,0.22]
	d.	[0.28,0.22]