IQ scores are normally distributed with a mean of 105 and a standard deviation of 17. Assume that many samples of size n are taken from a large population of people and the mean IQ score is computed for each sample. If the sample size is n 81, find the mean and standard deviation of the distribution of sample means.

Respuesta :

Answer:

Mean 105

Standard deviation 1.89

Step-by-step explanation:

The Central Limit Theorem estabilishes that, for a random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sample means with size n of at least 30 can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex]

In this problem, we have that:

[tex]\mu = 105, \sigma = 17[/tex]

If the sample size is n 81, find the mean and standard deviation of the distribution of sample means.

By the Central limit theorem

mean 105

Standard deviation

[tex]s = \frac{17}{\sqrt{81}} = 1.89[/tex]

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