Suppose that the mean weight of a certain type of pig is 280poundswith a standard deviation of80pounds. The weight distribution of pigs tends to be somewhat skewed to the right. A random sample of 100pigs is taken. Which of the following statements about

the sampling distribution of the sample mean weight xis true?

(a) It will be Normally distributed with a mean of 280poundsand a standard deviation of 80pounds.

(b) It will be Normally distributed with a mean of 280poundsand a standard deviation of 8pounds.

(c) It will be approximately Normally distributed with a mean of 280poundsand a standard deviation of 80pounds.

(d) It will be approximately Normally distributed with a mean of 280poundsand a standard deviation of 8pounds.

(e) There is not enough information to determine the mean and standard deviation of the sampling distribution.

Short Answer

Expert verified

The answer is 8so, option (d) is correct.

Step by step solution

01

Given information

We have been given that the distribution will be approximately normally distributed.

Now we choose correct option for the statement about the sampling distribution of the sample mean weightx¯is true.

02

Explanation

We cannot say that the distribution is exactly normally distributed, but since n>30we can say that by the central limit theorem, the distribution is approximately normal.

μ=280

The mean for a sample is the same as the population mean.

σ=8

σ=80100=8

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