you are the newly appointed assistant administrator at a local hospital, and your first project is to investigate the quality of the patient meals put out by the food-service department. you conducted a 10-day survey by submitting a simple questionnaire to the 400 patients with each meal, asking that they simply check off that the meal was either satisfactory or unsatisfactory. for simplicity in this problem, assume that the response was 1,000 returned questionnaires from the 1,200 meals each day. the results are as follows:

Respuesta :

Using the z-distribution, the 95% confidence interval for the proportion of unsatisfactory meals is given by:

(0.0553, 0.0647).

What is a confidence interval of proportions?

A confidence interval of proportions is given by the following rule:

[tex]\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]

In which:

  • [tex]\pi[/tex] is the sample proportion, which is also the estimate of the parameter.
  • z is the critical value.
  • n is the sample size.

The confidence level is of 95%, hence the critical value z is the value of Z that has a p-value of [tex]\frac{1+0.95}{2} = 0.975[/tex], so the critical value is z = 1.96.

The estimate and the sample size of the interval are given as follows:

[tex]\pi = \frac{600}{10000} = 0.06, n = 10000[/tex]

The lower bound of the interval is given by:

[tex]\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.06 - 1.96\sqrt{\frac{0.06(0.94)}{10000}} = 0.0553[/tex]

The upper bound of the interval is given by:

[tex]\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.06 + 1.96\sqrt{\frac{0.06(0.94)}{10000}} = 0.0647[/tex]

Hence the interval in (LCL, UCL) format is:

(0.0553, 0.0647).

What is the missing information?

The problems asks for the 95% confidence interval of unsatisfactory meals, considering that, out of 10000 meals, 600 were unsatisfactory.

More can be learned about the z-distribution at https://brainly.com/question/25890103

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