Respuesta :
Answer:
The probability that the sample mean will be between 25.5 and 27 years is 0.1359.
Step-by-step explanation:
Let X denote of age of JSOM students.
The information provided is:
[tex]\mu=24\\\sigma=9\\n=36[/tex]
According to the Central Limit Theorem if an unknown population is selected with mean μ and standard deviation σ and appropriately huge random samples (n > 30) are selected from this population with replacement, then the distribution of the sample means will be approximately normally.
Then, the mean of the sample means is given by,
[tex]\mu_{\bar x}=\mu\\[/tex]
And the standard deviation of the sample means is given by,
[tex]\sigma_{\bar x}=\frac{\sigma}{\sqrt{n}}[/tex]
As the sample size is large, i.e. n = 36 > 30, the sampling distribution of the average age of all the JSOM students can be approximated by the normal distribution.
Compute the probability that the sample mean will be between 25.5 and 27 years as follows:
[tex]P(25.5<\bar X<27)=P(\frac{25.5-24}{9/\sqrt{36}}<\frac{\bar X-\mu_{\bar x}}{\sigma_{\bar x}}<\frac{27-24}{9/\sqrt{36}})\\\\=P(1<Z<2)\\\\=P(Z<2)-P(Z<1)\\\\=0.97725-0.84134\\\\=0.13591\\\\\approx 0.1359[/tex]
Thus, the probability that the sample mean will be between 25.5 and 27 years is 0.1359.
