In a recent poll of 750750 randomly selected​ adults, 589589 said that it is morally wrong to not report all income on tax returns. Use a 0.050.05 significance level to test the claim that 7575​% of adults say that it is morally wrong to not report all income on tax returns. Identify the null​ hypothesis, alternative​ hypothesis, test​ statistic, P-value, conclusion about the null​ hypothesis, and final conclusion that addresses the original claim. Use the​ P-value method. Use the normal distribution as an approximation of the binomial distribution.

Respuesta :

Answer:

We conclude that % of adults who say that it is morally wrong to not report all income on tax returns is different from 75%.

Step-by-step explanation:

We are given that in a recent poll of 750 randomly selected​ adults, 589 said that it is morally wrong to not report all income on tax returns.

We have to test the claim that 75% of adults say that it is morally wrong to not report all income on tax returns.

Let p = % of adults who say that it is morally wrong to not report all income on tax returns.

So, Null Hypothesis, [tex]H_0[/tex] : p = 75%      {means that % of adults who say that it is morally wrong to not report all income on tax returns is 75%}

Alternate Hypothesis, [tex]H_0[/tex] : p [tex]\neq[/tex] 20%      {means that % of adults who say that it is morally wrong to not report all income on tax returns is different from 75%}

The test statistics that would be used here One-sample z proportion statistics;

                       T.S. =  [tex]\frac{\hat p-p}{\sqrt{\frac{\hat p(1-\hat p)}{n} } }[/tex]  ~ N(0,1)

where, [tex]\hat p[/tex] = sample proportion of adults who said that it is morally wrong to not report all income on tax returns = [tex]\frac{589}{750}[/tex] = 0.785

           n = sample of adults = 750

So, test statistics  =  [tex]\frac{0.785-0.75}{\sqrt{\frac{0.785(1-0.785)}{750} } }[/tex]

                               =  2.33

The value of z test statistics is 2.33.

Now, P-value of the test statistics is given by the following formula;

           P-value = P(Z > 2.33) = 1 - P(Z [tex]\leq[/tex] 2.33)

                         = 1 - 0.9901 = 0.0099

Also, P-value for two-tailed test is calculated as = 2 [tex]\times[/tex] 0.0099 = 0.0198

Since, the P-value of test statistics is less than the level of significance as 0.0198 < 0.05, so we have sufficient evidence to reject our null hypothesis as it will fall in the rejection region due to which we reject our null hypothesis.

Therefore, we conclude that % of adults who say that it is morally wrong to not report all income on tax returns is different from 75%.