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Recent questions tagged statistics

3 votes
2 answers
1
For two data sets, each of size $5$, the variances are given to be $4$ and $5$ and the corresponding means are given to be $2$ and $4$ respectively. The variance of the combined data is? $11/2$ $6$ $13/2$ $5/2$
asked Dec 27, 2018 in Probability Ruturaj Mohanty 311 views
2 votes
1 answer
2
A class of first year B.tech students is composed of four batches A, B, C and D, each consisting of $30$ students. It is found that the sessional marks of students in Engineering Drawing in batch C have a mean of $6.6$ and standard deviation of $2.3$. The mean and the standard deviation of ... class. Due to this, the marks of a student in batch C are changed from $8.5$ to $6.0$ $7.0$ $8.0$ $9.0$
asked Dec 27, 2018 in Probability Ruturaj Mohanty 264 views
1 vote
1 answer
3
The following sequence of numbers is arranged in increasing order: $1,x,x,x,y,y,9,16,18$. Given that the mean and median are equal, and are also equal to twice the mode, the value of $y$ is $5$ $6$ $7$ $8$
asked Mar 26, 2018 in Numerical Ability Milicevic3306 343 views
1 vote
1 answer
4
The second moment of a Poisson-distributed random variable is 2. The mean of the variable is .... My question on solving we get 2 values of lamda(ie mean) .One is -2 and the other is 1 .So which one to choose?
asked Nov 23, 2017 in Mathematical Logic Kalpataru Bose 1.1k views
1 vote
0 answers
5
For what value of 'k' (in terms of $X_{i}$'s) following functions will attain their minimum value $\rightarrow$ $F_{1}(k)$ = $\sum_{i=0}^{n} \left | X_{i} - k \right |$ $F_{2}(k)$ = $\sum_{i=0}^{n}\left ( X_{i} - k \right )^{2}$ If possible, please provide some valid proof for supporting your answer ?
asked Nov 11, 2017 in Probability Chhotu 89 views
0 votes
1 answer
6
the harmonic mean of two positive integers p and q is 3, given that [ (6p+1)/(7q-4) ] <(p/q), what could be the value of q? a)q<=4 b)q>9 c)q<8 d)q>=13
asked May 15, 2017 in Numerical Ability Angkit 140 views
1 vote
1 answer
7
In a company with $100$ employees, $45$ earn $Rs. 20,000$ per month, $25$ earn $Rs. 30000$, $20$ earn $Rs. 40000$, $8$ earn $Rs. 60000$, and $2$ earn $Rs. 150,000$. The median of the salaries is $Rs. 20,000$ $Rs. 30,000$ $Rs. 32,300$ $Rs. 40,000$
asked Feb 27, 2017 in Numerical Ability Arjun 155 views
4 votes
2 answers
8
Students taking an exam are divided into two groups, P and Q such that each group has the same number of students. The performance of each of the students in a test was evaluated out of $200$ marks. It was observed that the mean of group P was $105$, while that of ... Most students of group Q scored marks in a narrower range than students in group P. The median of the marks of group P is $100$.
asked Jan 20, 2017 in Numerical Ability makhdoom ghaya 1.1k views
2 votes
1 answer
9
3 votes
3 answers
10
What is the median of data if its mode is 15 and the mean is 30? 30 25 22.5 27.5
asked Jun 27, 2016 in Probability Aryan 2.9k views
4 votes
3 answers
11
The arithmetic mean of attendance of 49 students of class A is 40% and that of 53 students of class B is 35%. Then the percentage of arithmetic mean of attendance of class A and B is 27.2% 50.25% 51.13% 37.4%
asked Jun 23, 2016 in Probability jothee 2k views
3 votes
1 answer
12
If the mean of a normal frequency distribution of 1000 items is 25 and its standard deviation is 2.5, then its maximum ordinate is $\frac{1000}{\sqrt{2 \pi} } e^{-25}$ $\frac{1000}{\sqrt{2 \pi} }$ $\frac{1000}{\sqrt{2 \pi} } e^{-2.5}$ $\frac{400}{\sqrt{2 \pi} }$
asked Jun 15, 2016 in Probability jothee 2.1k views
8 votes
5 answers
13
The statistics of runs scored in a series by four batsmen are provided in the following table. Who is the most consistent batsman of these four? ... $K$ $L$ $M$ $N$
asked Mar 18, 2016 in Numerical Ability makhdoom ghaya 2k views
2 votes
2 answers
14
The arithmetic mean of five different natural numbers is $12$. The largest possible value among the numbers is $12$ $40$ $50$ $60$
asked Feb 16, 2016 in Numerical Ability Akash Kanase 692 views
1 vote
1 answer
15
what is positively skewed ,symmetric and negatively skewed distribution?
asked Dec 25, 2015 in Probability Amey 499 views
5 votes
2 answers
16
Let $A$ and $B$ be non-empty disjoint sets of real numbers. Suppose that the average of the numbers in the first set is $\mu_{A}$ and the average of the numbers in the second set is $\mu_{B}$; let the corresponding variances be $v_{A}$ and $v_{B}$ respectively. If the average of the elements in $A \cup B$ ... $p.v_{A}+ (1 - p). v_{B} + (\mu_{A}- \mu_{B})^{2}$
asked Dec 5, 2015 in Numerical Ability makhdoom ghaya 342 views
3 votes
2 answers
17
Q) Let $x$ be normal variable with mean $8$ and standard deviation $4$ then $p(X\leq5)$ is A). Greater than zero but less than $0.5$ B). Greater than $0.75$ C). Greater than $0.5$ but less than $1$ D). Equal to $0.5$
asked Dec 3, 2015 in Probability richa116 591 views
11 votes
2 answers
18
Which of the following assertions are CORRECT? P: Adding $7$ to each entry in a list adds $7$ to the mean of the list Q: Adding $7$ to each entry in a list adds $7$ to the standard deviation of the list R: Doubling each entry in a list doubles the mean of the list S: Doubling each entry in a list leaves the standard deviation of the list unchanged $P$, $Q$ $Q$, $R$ $P$, $R$ $R$, $S$
asked Sep 29, 2014 in Numerical Ability gatecse 1.9k views
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