"(1) n=1048,p=0.42"
(2) Let "H_o: p<0.5" , Half of the U.S. adults believe that global warming is greatly exaggerated
and "H_a: p>0.5," Not half of the US adults believe that global warming is greatly exaggerated.
Here, \hat{p}=0.5,
Test statistics-
"z=\\dfrac{0.5-0.42}{\\sqrt{\\frac{0.42(1-0.42)}{1048}}}=\\dfrac{0.08\\times 32.37}{0.4935}=5.2474"
"\\text{P-value-}\n\\\\\n p(z<5.2474)=1"
As "p-value>\\alpha i.e. 0.05" , So Null hypothesis is accepted. There is enough evidence to support the claim that Half of the US adults believe that global warming is greatly exaggerated.
(3) p_1=0.68,p_2=0.18,n_1=400,n_2=450
(4) Let "H_o: p_2'<p_1'," fewer Democrats think global warming is exaggerated than Republicans
and "H_a:p_2'>p_1'," The claim is wrong.
Test statistics-
"z=\\dfrac{p_1-p_2}{\\sqrt{\\dfrac{p_1(1-p_1)}{n_1}+\\dfrac{p_2(1-p_2)}{n_2}}}\\\\[9pt]=\\dfrac{0.68-0.18}{\\sqrt{\\dfrac{0.68(1-0.68)}{400}+\\dfrac{0.18(1-0.18)}{450}}}"
"\\\\[9pt]=\\dfrac{0.5}{0.029}=32.804"
"P(value) =P(z>32.804)=1"
As "p-value>\\alpha," so Null hypothesis is accepted, There is enough evidence to support the claim that fewer Democrats think global warming is exaggerated than Republicans
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