Answer: z(e) = 2.07
Explanation:
1.-The problem is about a test of proportions. As research company claims than no more 55 % of Americans regularly watch Fox News
The null hypothesis is H₀ P₀ ≤ 0.55 from 55%
And the alternative hypothesis is Hₐ Pₐ > .55
Is one tail test
2.-We have to specify significance level we assume our test will be for a significance level α = 5% or α = 0,05
3.-Calculation of z (c) = ?? and z (e) = '??
For z (c) we find in z table the value of z(c) = 1.64
For z (e) = ( P -P₀)/√p₀q₀/n z(e) = 0.05 / √(0.55*0,45)/425 z(e) = 0,05/ 0.02413 z(e) = 2.07
z(e) > z(c) threfore z(e) is in the rejection zone . We reject null hyothesis