58 believe in global warming A recent poll interviewed 1059

58% believe in global warming. A recent poll interviewed 1059 adults and 638 said they believe in global warming. What is the null and alternative hypothesis, z-statistic, p-value, support or reject the null?

Solution

Null hypothesis: p=0.58

Alternative hypothesis: p not equal to 0.58

The test statistic is

Z=(phat-p)/sqrt(p*(1-p)/n)

=(638/1059-0.58)/sqrt(0.58*(1-0.58)/1059)

=1.48

It is a two-tailed test.

The p-value= P(Z>1.48) =0.0694 (from standard normal table)

Assume that the significant level a=0.05

Since the p-value is larger than 0.05, we do not reject the null hypothesis.

So we can conclude that 58% believe in global warming.