題組內容

Q6. (15%) Survey has been widely used by politicians around the world as a way of monitoring the opinions of electorate. Three months ago, a survey was undertaken to determine the degree of support for a national party leader. Of a sample of 1100, 56% indicated that they would vote for this politician. This month, another survey of 800 voters revealed that 46% now support the leader.

(a) Estimate with 98% confidence the decrease in percentage support between now and 3 months ago.