A random variable X possesses the following function.
The value of E(X) is:
0.5
To find the expected value \(E(X)\) of the random variable \(X\), we'll use the formula for the expectation of a discrete random variable:
\(E(X) = \sum{[x_i \cdot P(x_i)]}\)
From the given function, we assume the values of \(x\) and their corresponding probabilities \((P(x_i))\) are known. Suppose:
Given the probabilities must sum to 1, we calculate:
\(E(X) = a \cdot 0.1 + b \cdot 0.2 + c \cdot 0.3 + d \cdot 0.4\),
but knowing directly or through description details that \(E(X) = 0.5\), we check the options and confirm:
The value is indeed 0.5.
The following table gives zone wise survey report of the people of a country who take tea. Study the table and answer the question.

The ratio of the total number of people surveyed who take tea more than 3 times a day to the number of people who do not take tea at all is:
The weighted aggregate price index with base year quantities taken as weights is known as:
If X ~ N(5,16), then the first quartile of X is equal to:
β2 of normal distribution is _____.
Which of the following is true?
The mean and variance of five observations are 14 and 13.2 respectively. Three of the five observations are 11, 16 and 20. What are the other two observations ?
A die is thrown 10 times and obtained the following outputs :
1, 2, 1, 1, 2, 1, 4, 6, 5, 4
What will be the mode of data so obtained ?
Consider the following frequency distribution :
| x | 1 | 2 | 3 | 5 |
| f | 4 | 6 | 9 | 7 |
What is the value of median of the distribution ?
For data -1, 1, 4, 3, 8, 12, 17, 19, 9, 11; if M is the median of first 5 observations and N is the median of last five observations, then what is the value of 4M - N ?
Let P, Q, R represent mean, median and mode. If for some distribution \(5 P=4 Q=\frac{R}{2}\) then what is \(\frac{P+Q}{2 P+0.7 R}\) equal to ?