Exams
Subjects
Classes
Home
Exams
Mathematics
Variance and Standard Deviation
the mean of 5 observation...
Question:
medium
The mean of 5 observations is
\(\frac {24}{5}\)
and variance is
\(\frac {194}{25}\)
. If the mean of first four observations is
\(\frac 72\)
, then the variance of first four observations is
JEE Main - 2024
JEE Main
Updated On:
Jan 13, 2026
\(\frac 32\)
\(\frac 52\)
\(\frac 54\)
\(\frac 23\)
Show Solution
The Correct Option is
C
Solution and Explanation
Option (C) is correct:
\(\frac 54\)
.
Download Solution in PDF
Was this answer helpful?
2
Top Questions on Variance and Standard Deviation
Let mean and variance of 6 observations a, b, 68, 44, 40, 60 be 55 and 194. If a > b then find a + 3b
JEE Main - 2024
Mathematics
Variance and Standard Deviation
View Solution
Given data
\(60, 60, 44, 58, 68, α, β, 56\)
has mean
\(58\)
, variance =
\(66.2\)
, then find
\(α^2 + β^2\)
.
JEE Main - 2024
Mathematics
Variance and Standard Deviation
View Solution
From a lot of 12 items containing 3 defectives, a sample of 5 items is drawn at random. Let the random variable $X$ denote the number of defective items in the sample. Let items in the sample be drawn one by one without replacement. If the variance of $X$ is $\frac{m}{n}$, where $\gcd(m, n) = 1$, then $n - m$ is equal to ________.
JEE Main - 2024
Mathematics
Variance and Standard Deviation
View Solution
The mean and standard deviation of 20 observations are found to be 10 and 2, respectively. On respectively, it was found that an observation by mistake was taken 8 instead of 12. The correct standard deviation is
JEE Main - 2024
Mathematics
Variance and Standard Deviation
View Solution
Want to practice more? Try solving extra ecology questions today
View All Questions
Questions Asked in JEE Main exam
A long straight wire of circular cross-section (radius \( a \)) is carrying a steady current \( I \). The current \( I \) is uniformly distributed across this cross-section. The magnetic field is:
JEE Main - 2023
VITEEE - 2024
Modern Physics
View Solution
The resistivity (\( \rho \)) of a semiconductor varies with temperature. Which of the following curves represents the correct behavior?
JEE Main - 2023
VITEEE - 2024
Electrostatics
View Solution
Which of the following has a square pyramidal shape?
JEE Main - 2024
Hybridisation
View Solution
Statement I:
Since fluorine is more electronegative than nitrogen, the net dipole moment of NF
3
is greater than NH
3
.
Statement II:
In NH
3
, the orbital dipole due to the lone pair and the dipole moment of NH bonds are in opposite directions, but in NF
3
, the orbital dipole due to the lone pair and the dipole moments of N-F bonds are in the same direction.
In light of the above statements, choose the most appropriate from the options given below:
JEE Main - 2024
Chemical bonding and molecular structure
View Solution
Decreasing order of electron gain enthalpy of the following elements (magnitude only)
Sulphur A, Bromine - B, Fluorine C, Argon D
JEE Main - 2024
Enthalpy change
View Solution