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.

Some important characteristics of population include ___________. A: genetics B: natality and mortality C: sex ratio and age distribution D: density and spatial distribution.

"Economic efficiency" means ( ) A: Satisfying needs, rational allocation and fair distribution. B: Reasonable allocation, fair distribution and ecological balance. C: Equitable distribution, ecological balance and full employment. D: Satisfying needs, full employment and reasonable allocation.

Let [img=47x25]1803a319caed5c0.png[/img] be the uniformly distributed within the unit circle, and the the joint probability density function be [img=501x61]1803a319d67d32e.png[/img]Then the marginal distribution of X in [img=47x25]1803a319caed5c0.png[/img] is also the uniform 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.

EBD, short for Electronic Brake-force Distribution, as the subsystem of ABS, is designed to automatically modulate the brake force on the front wheels and the rear wheels according to the load of the car, the condition of the road and the adhesion between the tire sand road surface in order to get more balanced and closer to the ideal brake force distribution．

The<br/>population inversion distribution is also called as() A: Negative<br/>temperature distribution B: Boltzmann<br/>distribution C: Thermal<br/>equilibrium distribution D: Maxwell<br/>distribution

A standard normal distribution is a normal distribution with:

All the allomorphs should be in complementary distribution.