2
If two random variables $X$ and $Y$ are connected by relation
$\frac{2 X-3 Y}{5 X+4 Y}=4$ and $X$ follows Binomial distribution with parameters $n=10$ and $p=\frac{1}{2}$, then what is the variance of $Y$ ?
NDA Mathematics 21 April 2024
4
$$
\text { What is } \sum_i^n x_i f_i \text { equal to? }
$$
NDA Mathematics 21 April 2024
8
The sum of deviations of n numbers from 10 and 20 are p and q respectively. If (p - q)2 = 10000, then what is the value of n?
NDA Mathematics 3 September 2023
9
If X̅ = 20 is the mean of 10 observations x1, x2, ... x10; then what is the value of $\displaystyle \sum_{i=1}^{10}\left(\frac{3 x_i-4}{5}\right) ?$ ?
NDA Mathematics 3 September 2023
10
If the mean and the sum of squares of 10 observations are 40 and 16160 respectively, then what is the standard deviation?
NDA Mathematics 3 September 2023
11
If r is the coefficient of correlation between x and y, then what is the correlation coefficient between (3x + 4) and (-3y + 3)?
NDA Mathematics 3 September 2023
12
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 ?
NDA Mathematics 16 April 2023
13
The central angles p, q, r and s (in degrees) of four sectors in a Pie Chart satisfy the relation 9p = 3q = 2r = 6s. What is the value of 4p - q ?
NDA Mathematics 16 April 2023
14
The observations 4, 1, 4, 3, 6, 2, 1, 3, 4, 5, 1, 6 are outputs of 12 dices thrown simultaneously. If m and M are means of lowest 8 observations and highest 4 observations respectively, then what is (2m + M) equal to ?
NDA Mathematics 16 April 2023
17
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 ?
NDA Mathematics 16 April 2023
18
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 ?
NDA Mathematics 16 April 2023
20
The coefficient of correlation between ages of husband and wife at the time of marriage for a given set of 100 couples was noted to be 0.7. Assume that all these couples survive to celebrate the silver jubilee of their marriage. The coefficient of correlation at that point of time will be
NDA Mathematics 4 September 2022
26
The frequency curve (assuming unimodal) corresponding to the data obtained in an experiment is skewed to the left. What conclusion can be drawn from the curve ?
NDA Mathematics 10 April 2022
27
The variance of five positive observations is 3.6. If four of the observations are 2, 2, 4, 5 then what is the remaining observation ?
NDA Mathematics 10 April 2022
28
What is the coefficient of mean deviation of 21, 34, 23, 39, 26, 37, 40, 20, 33, 27 (taken from mean)?
NDA Mathematics 10 April 2022
29
What is the mean of the values?
NDA Mathematics 10 April 2022
30
What is the algebraic sum of the deviations of the same set of values measured from 99?
NDA Mathematics 10 April 2022
31
If the algebraic sum of the deviations of the same set of values measured from y is 180, then what is the value of y ?
NDA Mathematics 10 April 2022
34
If the frequency of each class is doubled, then what would be the mean?
NDA Mathematics 10 April 2022
35
If M is the mean of n observations x1 - k, x2 - k, x3 - k, _ _ _, xn - k, where k is any real number, then what is the mean of x1, x2, x3, _ _ _, xn?
NDA Mathematics 18 April 2021
36
What is the sum of deviations of the variate values 73, 85, 92, 105, 120 from their mean?
NDA Mathematics 18 April 2021
37
If the mean of a frequency distribution is 100 and the coefficient of variation is 45%, then what is the value of the variance?
NDA Mathematics 18 April 2021
38
For which of the following sets of numbers do the mean, median and mode have the same value?
NDA Mathematics 18 April 2021
39
The mean of 12 observations is 75. If two observation are discarded, then the mean of the remaining observations is 65. What is the mean of the discarded observations?
NDA Mathematics 18 April 2021
40
The average of a set of 15 observations is recorded, but later it is found that for one observation, the digit in the tens place was wrongly recorded as 8 instead of 3. After correcting the observation, the average is
NDA Mathematics 18 April 2021
41
If the mode of the scores 10, 12, 13, 15, 15, 13, 12, 10, x is 15, then what is the value of x?
NDA Mathematics 18 April 2021
43
The numbers of Science, Arts and Commerce graduates working in a company are 30, 70 and 50 respectively. If these figures are represented by a pie chart, then what is the angle corresponding to Science graduates?
NDA Mathematics 18 April 2021
44
For a histogram based on a frequency distribution with unequal class intervals, the frequency of a class should be proportional to:
NDA Mathematics 18 April 2021
45
The co-efficient of correlation is independent of:
NDA Mathematics 18 April 2021