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As the sample size increases, the variability among the sample means _____.

a. increases
b. decreases
c. remains the same
d. depends upon the specific population being sampled

1 Answer

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Final answer:

The variability among sample means decreases as the sample size increases, leading to more precise and reliable statistical estimates.

Step-by-step explanation:

As the sample size increases, the variability among the sample means decreases. This concept is rooted in the principles of statistics, particularly within the realm of the Central Limit Theorem. According to this theorem, as the size of the sample (n) becomes larger, the distribution of the sample means will tend to approximate a normal distribution (regardless of the shape of the population distribution), with a standard deviation that is equal to the population standard deviation divided by the square root of the sample size. This means that the standard deviation of the sampling distribution (also known as the standard error) decreases as the sample size increases.

This effect also relates to confidence intervals. With a larger sample size, the error bound of a confidence interval decreases, resulting in a narrower, more precise confidence interval. Thus, for larger samples, we can be more confident that the sample mean is close to the actual population mean, and we observe less variability in sample means compared to smaller samples.

In summary, the variability among sample means decreases as the sample size increases, leading to more reliable statistical estimates and a greater likelihood of accurately capturing the true population mean.

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