Small sample: During an economic downturn, companies were sampled and asked whether they were planning to increase their workforce. Only of the companies were planning to increase their workforce. Use the small-sample method to construct a confidence interval for the proportion of companies that are planning to increase their workforce. Round the answers to at least three decimal places. A confidence interval for the proportion of companies that are planning to increase their workforce is .

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Complete Question

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Answer:

The confidence level interval is  [tex]0.016 \le C \le 0.404[/tex]

Step-by-step explanation:

The sample size is  [tex]n = 20[/tex]

The number planning to increase workforce is  [tex]x = 3[/tex]

 The confidence level is  [tex]c = 98[/tex]%

The value of proportion for a plus 4 method is

      [tex]p = \frac{x+2}{n+4}[/tex]

substituting values

      [tex]p = \frac{3+2}{20+4}[/tex]

       [tex]p =0.21[/tex]

The z-critical value at confidence level of 98% is

     [tex]z_{c}=z_{0.98} = 2.33[/tex]

This values is obtained from the standard normal table

The confidence level interval can be mathematically represented as

      [tex]C =p \ \pm z_{c} * \sqrt{\frac{p(1-p)}{n+4} }[/tex]

substituting values

      [tex]C = 0.21 \pm 2.33 * \sqrt{\frac{0.21(1- 0.21)}{20 +4} }[/tex]

       [tex]C = 0.21 \pm 0.194[/tex]

=>   [tex]0.016 \le C \le 0.404[/tex]

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