Question

Help

QUESTION w A random sample of 450 registered voters in Phoenix is asked if they favor the use of oxygenated fuels year-round to reduce air pollution. If more than 360 voters respond positively, Can we conclude that more than 60% of the voters favor the use of these fuels Use Alpha=0.05 Yes Not able to decide No Missing information

Answer 1

Here claim is that p>0.60

And $\widehat{p}=\frac{360}{450}=0.8$

Hence test statistics is $z=\frac{\widehat{p}-p}{\sqrt{\frac{pq}{n}}}=\frac{0.8-0.6}{\sqrt{\frac{0.6*0.4}{450}}}=8.66$

Hence P value is $P(z>8.66)=0<\alpha=0.05$

As we have P value less than alpha we reject the null hypothesis

Hence we have sufficient evidence to support the claim that p>0.60

So answer here is Yes