Which of the following is true about the sampling distribution of the sample mean?
A: The mean of the sampling distribution is always μ.
B: The standard deviation of the sampling distribution is always σ.
C: The shape of the sampling distribution is always approximately normal.
D: D) All the alternatives are correct
A: The mean of the sampling distribution is always μ.
B: The standard deviation of the sampling distribution is always σ.
C: The shape of the sampling distribution is always approximately normal.
D: D) All the alternatives are correct
举一反三
- As a general rule, the normal distribution is used to approximate the sampling distribution of the sample mean only if
- Which of the following about the normal distribution is NOT true? A: Theoretically, the mean, median, and mode are the same B: About 68% of the observations fall within ±1 standard deviation from the mean C: Its parameters are the mean, μ, and standard deviation, σ D: It is a discrete probability distribution.
- If n samples are extracted from any population with mean value [img=11x18]1803dc1a4012523.png[/img] and variance [img=18x22]1803dc1a48a9511.png[/img], then A: When n is sufficiently large, the distribution of sample mean is approximately normal distribution. B: When n<10, the distribution of sample mean is approximately normal distribution. C: The distribution of sample mean is nothing to do with n. D: No matter how big n is, the distribution of the sample mean is not going to be close to a normal distribution.
- 2.Which of the following about the normal distribution is NOT true A: Theoretically, the mean, median, and mode are the same. B: About 2/3 of the observations fall within ±1 standard deviation from the mean. C: It is a discrete probability distribution. D: Its parameters are the mean, μ, and standard deviation, σ.
- 中国大学MOOC: A population distribution is normal with a mean of 18 and standard deviation of 4. A sample of 16 observations is selected and a sample mean computed. What is the probability that the sample mean is more than 18?