Answer with explanation:
Let p be the proportion of voters in a certain state support an increase in the minimum wage.
As per given , we have

Since alternative hypothesis is right-tailed so the test is a right-tailed test.
Test statistic :

, where n= sample size.
p= population proportion.
= sample proportion.
. In a random sample of 300 fast food workers for 240 supporters increase an minimum-wage.
i.e. n= 300 and

Then,

For significant level α = .05 , the critical z-value is

Decision : Since calculated z-value (3.78) is greater than the critical value (1.645) , so we reject the null hypothesis.
Conclusion : We have sufficient evidence o support researcher's claim that that the percentage of fast food workers for support and increase is higher than 70%..