A: The mean is a measure of the middle (centre) of a distribution.
B: Half of the observations are on either side of the mean.
C: The sum of the deviations from the mean is zero.
D: The value of the mean times the number of observations equals the sum of all of the observations.
举一反三
- 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.
- 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
- 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?
- When analyzing investment returns, which of the following statements is correct? A: The geometric mean will exceed the arithmetic mean for a series with non-zero variance. B: The geometric mean measures an investment’s compound rate of growth over multiple periods. C: The arithmetic mean accurately estimates an investment’s terminal value over multiple periods.
内容
- 0
Given an infinite population with a mean of 75 and a standard deviation of 12, the probability that the mean of a sample of 36 observations, taken at random from this population, exceeds 78 is:
- 1
WhichofthefollowingstatementsconcerningadistributionwithpositiveskewnessandpositiveexcesskurtosisisFALSE（） A: The mean will be greater than the mode. B: It has a lower percentage of small deviations from the mean than a normal distribution. C: There are a large number of positive outliers.
- 2
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.
- 3
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.
- 4
The arithmetic mean is computed by ( ) A: finding the value that occurs most often B: finding the middle observation and dividing by 2 C: summing the values and dividing by the number of values. D: selecting the value in the middle of the data set.