The mayor of a town has proposed a plan for the construction of a new community. A political study took a sample of 1300 voters in the town and found that 45% of the residents favored construction. Using the data, a political strategist wants to test the claim that the percentage of residents who favor construction is more than 42%. Find the value of the test statistic. Round your answer to two decimal places.

Respuesta :

Answer:

The value of the test statistic is t = 2.19.

Step-by-step explanation:

Central Limit Theorem

For a proportion p in a sample of size n, the sampling distribution of the sample proportion will be approximately normal with mean [tex]\mu = p[/tex] and standard deviation [tex]s = \sqrt{\frac{p(1-p)}{n}}[/tex]

Our test statistic is:

[tex]t = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}[/tex]

In which X is the sample mean, [tex]\mu[/tex] is the expected mean, [tex]\sigma[/tex] is the standard deviation and n is the size of the sample.

Sample of 1300 voters:

This means that [tex]n = 1300[/tex]

Found that 45% of the residents favored construction.

This means that [tex]X = 0.45[/tex]

A political strategist wants to test the claim that the percentage of residents who favor construction is more than 42%.

This means that [tex]\mu = 0.42[/tex], and by the Central Limit Theorem:

[tex]\frac{\sigma}{\sqrt{n}} = s = \sqrt{\frac{0.42*0.58}{1300}} = 0.0137[/tex]

So, the test statistic is:

[tex]t = \frac{X - \mu}{s}[/tex]

[tex]t = \frac{0.45 - 0.42}{0.0137}[/tex]

[tex]t = 2.19[/tex]

The value of the test statistic is t = 2.19.