In 2018, RAND Corporation researchers found that 71% of all individuals ages 66 to 69 are adequately prepared financially for retirement. Many financial planners have expressed concern that a smaller percentage of those in this age group who did not complete high school are adequately prepared financially for retirement.

In a random sample of 300 people from the 66-69 age group who did not complete high school, 165 were not prepared financially for retirement. What is the p-value for your hypothesis test (to 4 decimals)? If your answer is zero, enter "0".

Respuesta :

Using the z-distribution, as we are working with a proportion, it is found that the p-value of the test is of 0.

What are the hypothesis tested?

At the null hypothesis, it is tested if the proportion is of 71%, that is:

[tex]H_0: p = 0.71[/tex]

At the alternative hypothesis, it is tested if the proportion has decreased, that is:

[tex]H_1: p < 0.71[/tex].

What is the test statistic?

The test statistic is given by:

[tex]z = \frac{\overline{p} - p}{\sqrt{\frac{p(1-p)}{n}}}[/tex]

In which:

  • [tex]\overline{p}[/tex] is the sample proportion.
  • p is the proportion tested at the null hypothesis.
  • n is the sample size.

In this problem, we have that the parameters are:

[tex]n = 300, \overline{p} = \frac{165}{300} = 0.55[/tex]

Hence, the value of the test statistic is found as follows:

[tex]z = \frac{\overline{p} - p}{\sqrt{\frac{p(1-p)}{n}}}[/tex]

[tex]z = \frac{0.55 - 0.71}{\sqrt{\frac{0.71(0.29)}{300}}}[/tex]

z = -6.11

What is the p-value of the test?

Using a z-distribution calculator, with a left-tailed test, as we are testing if the proportion is less than a value, and z = -6.11, it is found that the p-value is of 0.

More can be learned about the z-distribution at https://brainly.com/question/26454209

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