Question

During the recent primary elections, the democratic presidential candidate showed the following pre-election voter support in Alabama and Mississippi.

State	Voters Surveyed	Voters in favor of Democratic Candidate
Alabama	710	352
Mississippi	915	480

We want to determine whether or not the PROPORTIONS of voters favoring the Democratic candidate were the same in both states. In other words, is the first proportion (p1) the same as (p2)? What formula, from this week’s Notations and Symbols, would be applicable in the hypothesis test? (Notice you are not doing a hypothesis test – you are saying which formula applies).

Answer 1

Answer:

Given that,

During the recent primary elections, the democratic presidential candidate showed the following pre-election voter support in Alabama and Mississippi.

Given table,

State	Voters Surveyed	Voters in favor of Democratic Candidate
Alabama	710	352
Mississippi	915	480

Let p₁ and p₂ be the population proportions of voters favoring the Democratic candidate in Alabama and Mississippi respectively.

The appropriate hypothesis are,

H₀: p₁ = p₂

H_a : p₁ p₂

Sample proportions,

pooled proportion p=

=

=832.535/1625

=0.512

Standard error of difference in proportions, SE =

=0.025

Test statistic:

Z=|p₁ -p_2|/SE

=|0.496-0.525|/0.025

=0.029/0.025

=1.16