Respuesta :
Using the normal distribution and the central limit theorem, it is found that:
[tex]P(246 \leq \bar{x} \leq 260) = 0.5693[/tex]
Normal Probability Distribution
In a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
- It measures how many standard deviations the measure is from the mean.
- After finding the z-score, we look at the z-score table and find the p-value associated with this z-score, which is the percentile of X.
- By the Central Limit Theorem, the sampling distribution of sample means of size n has standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].
In this problem:
- The mean is of [tex]\mu = 250[/tex].
- The standard deviation is of [tex]\sigma = 50[/tex].
- A sample of 36 is taken, hence [tex]n = 36, s = \frac{50}{\sqrt{36}} = 8.3333[/tex].
The probability of a sample mean between 246 and 260 is the p-value of Z when X = 260 subtracted by the p-value of Z when X = 246, hence:
X = 260:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
By the Central Limit Theorem
[tex]Z = \frac{X - \mu}{s}[/tex]
[tex]Z = \frac{260 - 250}{8.3333}[/tex]
[tex]Z = 1.2[/tex]
[tex]Z = 1.2[/tex] has a p-value of 0.8849.
X = 246:
[tex]Z = \frac{X - \mu}{s}[/tex]
[tex]Z = \frac{246 - 250}{8.3333}[/tex]
[tex]Z = -0.48[/tex]
[tex]Z = -0.48[/tex] has a p-value of 0.3156.
0.8849 - 0.3156 = 0.5693, hence:
[tex]P(246 \leq \bar{x} \leq 260) = 0.5693[/tex]
To learn more about the normal distribution and the central limit theorem, you can check https://brainly.com/question/24663213
