The actual time it takes to cook a 10 pound turkey is a normally distributed. Suppose that a random sample of 10 pound turkey’s is taken.

Given that an average of 2.9 hours and a standard deviation of .24 hours was found for a sample of 19 turkeys, calculate a 95% confidence interval for the average cooking time of a 10 pound turkey.

Respuesta :

Answer:

The interval is (2.7512, 2.8488)

Step-by-step explanation:

Given that:

The mean (μ) = 2.9 hours

The standard deviation (σ) = 0.24 hours

n = 14 pound turkey

The confidence interval (c) = 95% = 0.95

α = 1 - 0.95 = 0.05

[tex]\frac{\alpha }{2} = \frac{0.05}{2} = 0.025[/tex]

The Z score of [tex]\frac{\alpha }{2}[/tex] is the z score of 0.025 which is the same z score of 0.475 (0.5 - 0.025).

[tex]Z_{\frac{\alpha }{2} }=1.96[/tex]

[tex]\mu_x=\mu=2.9[/tex]

[tex]\sigma_x=\frac{\sigma}{\sqrt{n} }=\frac{0.24}{\sqrt{10} } =0.07589[/tex]

Therefore the margin of error E is given as

E =  [tex]Z_{\frac{\alpha }{2} } *\sigma_x[/tex]  = 1.96 × 0.0759 = 0.1488

The interval is [tex](\mu_x-E,\mu_x+E)[/tex] = (2.9 - 0.1488, 2.9 + 0.1488) = (2.7512, 2.8488)

The interval is (2.7512, 2.8488)