The Standard Normal Distribution has mean equal to
0
The Standard Normal Distribution is a special case of the normal distribution that has a mean equal to 0 and a standard deviation equal to 1.
Any normal distribution with mean μ and standard deviation σ can be converted into the standard normal distribution using the z-score transformation, z = (x − μ)/σ, which recenters the data around zero and rescales it to a standard deviation of 1.
This standardization allows different normal distributions to be compared on a common scale, and it is the reason the standard normal curve is perfectly symmetric about zero, with equal area on either side.
Hence, the mean of the standard normal distribution is 0, not 1, 2, or 1/2.
The sum of deviation taken from which of the descriptive statistical measures is always equal to zero?
| LIST-I | LIST-II | |
| A. Sampling error | I. | Values that describe the characteristics of a population |
| B. Parameters | II. | The standard deviation of the sampling distribution |
| C. Sampling fraction | III. | Variation among sample statistics due to change |
| D. Standard error | IV. | Proportion of the population contained in a sample |
Given below are two statements one is labelled as Assertion (A) and the other is labelled as
Reason (R).
Assertion (A): Additive model considers the total of various components resulting in the given
values of the over all time series and it is stated as:
$Y=T+C+S+I$
Reason (R): Multiplicative model assumes that the various components interact in a
multiplicative manner to produce the given values of the over all time series and
can be stated as $Y=T \times C \times S \times I$
In the light of the above statements, choose the most appropriate answer from the options given
below:
Match List - I with List - II.
| List - I | List - II |
| A. Sample proportion P = x/n | I. $\frac{\sigma}{\sqrt{n}}$ |
| B. Sample variance $S_1^2 = \frac{1}{n-1} \sum_{i=1}^{n}(xi-x̄)^2$ | II. $\sigma^2 \sqrt{\frac{2}{n}}$ |
| C. Sample variance $S^2 = \frac{1}{n} \sum_{i=1}^{n}(xi-x̄)^2$ | III. $\sigma^2 \sqrt{\frac{2}{(n-1)}}$ |
| D. Sample mean $\bar{x} = \frac{1}{n} \sum_{i=1}^{n}xi$ | IV. $\sqrt{\frac{\pi(1-\pi)}{n}}$ |
Choose the correct answer from the options given below :