Juniors at a high school own internet enabled devices at a rate of 71%. If 52 freshmen were sampled and only 58% of them owned internet enabled devices, is this enough proof to state that freshmen own these devices at a lower rate than juniors? Explain based on probability.

Respuesta :

Using the z-distribution, the p-value of the test is enough proof to state that freshmen own these devices at a lower rate than juniors.

What are the hypotheses tested?

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

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

At the alternative hypotheses, it is tested if the proportion is less than 71%, hence:

[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 given as follows:

[tex]\overline{p} = 0.58, p = 0.71, n = 52[/tex].

Hence, the test statistic is given by:

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

[tex]z = \frac{0.58 - 0.71}{\sqrt{\frac{0.71(0.29)}{52}}}[/tex]

z = -2.06.

What is the p-value of the test?

Using a z-distribution calculator, with z = -2.06, the p-value(which is the probability of finding a sample proportion of at most as the one found) is of 0.0197.

Since this p-value is less than the standard of 0.05, it is enough proof to state that freshmen own these devices at a lower rate than juniors.

More can be learned about the z-distribution at https://brainly.com/question/16313918

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