举一反三
- Theoretically, the mean, median, and mode are all equal for a normal distribution.
- 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.
- 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.
- 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.
- Which of the following statement concerning about the arithmetic mean is FALSE（） A: It is less than or equal to the geometric mean. B: It is a commonly used measure of central tendency. C: It is equal to the median and mode in symmetric distributions.
内容
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True or False: When constructing a frequency distribution, classes should be selected so that they are of equal width.
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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
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All other things equal, a 20% increase in the number of units sold will yield a 20% increase innet income. True or False? A: true B: false
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As a general rule, the normal distribution is used to approximate the sampling distribution of the sample mean only if
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Another term for average is ____________. A: variance B: mode C: median D: mean