1
JEE Main 2022 (Online) 27th June Morning Shift
+4
-1

Let X be a random variable having binomial distribution B(7, p). If P(X = 3) = 5P(x = 4), then the sum of the mean and the variance of X is :

A
$${105 \over {16}}$$
B
$${7\over {16}}$$
C
$${77\over {36}}$$
D
$${49\over {16}}$$
2
JEE Main 2022 (Online) 26th June Evening Shift
+4
-1

The mean and standard deviation of 50 observations are 15 and 2 respectively. It was found that one incorrect observation was taken such that the sum of correct and incorrect observations is 70. If the correct mean is 16, then the correct variance is equal to :

A
10
B
36
C
43
D
60
3
JEE Main 2022 (Online) 26th June Morning Shift
+4
-1

The mean of the numbers a, b, 8, 5, 10 is 6 and their variance is 6.8. If M is the mean deviation of the numbers about the mean, then 25 M is equal to :

A
60
B
55
C
50
D
45
4
JEE Main 2021 (Online) 31st August Evening Shift
+4
-1
The mean and variance of 7 observations are 8 and 16 respectively. If two observations are 6 and 8, then the variance of the remaining 5 observations is :
A
$${{92} \over 5}$$
B
$${{134} \over 5}$$
C
$${{536} \over {25}}$$
D
$${{112} \over 5}$$
JEE Main Subjects
Physics
Mechanics
Electricity
Optics
Modern Physics
Chemistry
Physical Chemistry
Inorganic Chemistry
Organic Chemistry
Mathematics
Algebra
Trigonometry
Coordinate Geometry
Calculus
EXAM MAP
Joint Entrance Examination