Week 5 Statistics 2 Questions | Prasnya
Prasnya
Continue with Google
Practice route
Statistics 2 - Week 5
Give Mock Test
Topic wise questions
Exam
Quiz 2
Subject
Statistics 2
Week
Week 5
117
Questions
5
Years
Showing
Q1-Q1 of 83
Type
All
Plus
Difficulty
All
Pro
Year
All
Pro
Q1
The joint PDF of two continuous random variables
X
X
and
Y
Y
is given by
f
X
Y
(
x
,
y
)
=
{
4
x
y
17
4
,
0
≤
x
≤
17
,
0
≤
y
≤
17
,
0
,
otherwise.
f_{XY}(x,y)=\begin{cases}\dfrac{4xy}{17^4}, & 0\le x\le 17,\ 0\le y\le 17,\\ 0, & \text{otherwise.}\end{cases}
Are
X
X
and
Y
Y
independent?
Single correct
medium
3 marks
APRIL 06, 2026
APRIL 06, 2026
Q2
Let
X
1
,
X
2
,
X
3
,
X
4
X_1, X_2, X_3, X_4
be i.i.d. Normal random variables. Find the value of
P
(
3
X
1
+
X
2
+
2
X
3
+
3
X
4
≤
17
)
P(3X_1+X_2+2X_3+3X_4\le 17)
.
Single correct
medium
3 marks
APRIL 06, 2026
APRIL 06, 2026
Q3
Enter the correct option number for __A__.
Comprehension
easy
0.5 marks
APRIL 06, 2026
APRIL 06, 2026
Q4
Enter the correct option number for __B__.
Comprehension
easy
0.5 marks
APRIL 06, 2026
APRIL 06, 2026
Q5
Enter the correct option number for __C__.
Comprehension
easy
0.5 marks
APRIL 06, 2026
APRIL 06, 2026
Q6
Enter the correct option number for __D__.
Comprehension
easy
0.5 marks
APRIL 06, 2026
APRIL 06, 2026
Q7
Enter the correct option number for __E__.
Comprehension
easy
0.5 marks
APRIL 06, 2026
APRIL 06, 2026
Q8
Let
(
X
,
Y
)
∼
Uniform
(
R
)
(X,Y)\sim \text{Uniform}(R)
, where
R
=
{
(
x
,
y
)
:
x
2
+
y
2
<
9
,
x
>
0
,
y
>
0
}
R=\{(x,y):x^2+y^2<9,\ x>0,\ y>0\}
. Find the value of
P
(
X
<
1
,
Y
<
2
)
P(X<1,Y<2)
. Enter the answer correct to two decimal places.
Integer answer
medium
2 marks
APRIL 06, 2026
APRIL 06, 2026
Q9
Which of the following statements is/are correct?
Comprehension
medium
2 marks
APRIL 06, 2026
APRIL 06, 2026
Q10
What is the marginal PDF of
X
X
at
x
=
50
x=50
?
Comprehension
medium
3 marks
APRIL 06, 2026
APRIL 06, 2026
Q11
A randomly selected patient from this age group is found to have an enzyme level of
50
50
U/L. What is the probability that the patient is healthy?
Comprehension
medium
2 marks
APRIL 06, 2026
APRIL 06, 2026
Q12
Which of the following statements is correct about the distribution of the sample mean?
Comprehension
easy
2 marks
APRIL 06, 2026
APRIL 06, 2026
Q13
Find the probability that the sample mean lifetime exceeds
506
506
hours. Enter the answer correct to two decimal places.
Comprehension
medium
3 marks
APRIL 06, 2026
APRIL 06, 2026
Q14
Let
X
X
and
Y
Y
be continuous random variables with joint PDF
f
X
,
Y
(
x
,
y
)
=
2
x
9
f_{X,Y}(x,y)=\frac{2x}{9}
,
0
≤
x
≤
2
0\le x\le2
,
1
≤
y
≤
3
1\le y\le3
, and
0
0
otherwise. Find
P
(
X
<
1
∣
Y
=
2
)
P(X<1\mid Y=2)
correct to two decimal places.
Integer answer
medium
3 marks
AUGUST 03, 2025
AUGUST 03, 2025
Q15
What is the marginal density function
f
X
(
x
)
f_X(x)
?
Comprehension
medium
3 marks
AUGUST 03, 2025
AUGUST 03, 2025
Q16
Find
P
(
0
<
X
<
1
,
Y
<
1
)
P(0<X<1,\ Y<1)
. Enter the answer correct to two decimal places.
Comprehension
medium
2 marks
AUGUST 03, 2025
AUGUST 03, 2025
Q17
What is the marginal distribution of
Y
Y
?
Comprehension
medium
2 marks
AUGUST 03, 2025
AUGUST 03, 2025
Q18
Find
f
X
∣
Y
=
0.4
(
1
)
f_{X|Y=0.4}(1)
. Enter the answer correct to two decimal places.
Comprehension
hard
3 marks
AUGUST 03, 2025
AUGUST 03, 2025
Q19
Which option is an acceptable approximate model for
Y
Y
as per the Central Limit Theorem?
Comprehension
medium
3 marks
AUGUST 03, 2025
AUGUST 03, 2025
Q20
Using the Central Limit Theorem, it is calculated that
P
(
Y
>
a
)
≈
0.0228
P(Y>a)\approx0.0228
. What is
a
a
? Use the useful standard normal data given in the question.
Comprehension
medium
2 marks
AUGUST 03, 2025
AUGUST 03, 2025
Q21
Let
(
X
,
Y
)
∼
U
n
i
f
o
r
m
(
D
)
(X,Y)\sim\mathrm{Uniform}(D)
where
D
=
{
(
x
,
y
)
:
x
+
y
<
2
,
x
>
0
,
y
>
0
}
D=\{(x,y):x+y<2,x>0,y>0\}
. What is the marginal density function of
X
X
?
Single correct
medium
3 marks
MARCH 16, 2025
MARCH 16, 2025
Q22
Find the value of
k
k
.
Comprehension
easy
2 marks
MARCH 16, 2025
MARCH 16, 2025
Q23
What is
P
(
X
<
1
/
2
,
Y
<
1
/
2
)
P(X<1/2,Y<1/2)
?
Comprehension
medium
3 marks
MARCH 16, 2025
MARCH 16, 2025
Q24
Which option(s) is/are correct?
Comprehension
easy
2 marks
MARCH 16, 2025
MARCH 16, 2025
Q25
Which option is an acceptable approximate model for
S
S
as per the Central Limit Theorem?
Comprehension
easy
2 marks
MARCH 16, 2025
MARCH 16, 2025
Q26
Using CLT, find an approximate probability that
S
S
lies between
40
40
and
48
48
heads. Enter the answer correct to two decimal places.
Comprehension
medium
2 marks
MARCH 16, 2025
MARCH 16, 2025
Q27
Let
X
1
,
X
2
,
…
,
X
10
X_1,X_2,\ldots,X_{10}
be i.i.d. random variables with common MGF
M
X
(
λ
)
M_X(\lambda)
. Find the MGF of
X
ˉ
\bar X
, where
X
ˉ
=
(
X
1
+
⋯
+
X
10
)
/
10
\bar X=(X_1+\cdots+X_{10})/10
.
Single correct
medium
3 marks
DECEMBER 01, 2024
DECEMBER 01, 2024
Q28
Let
X
X
be study hours and
Y
Y
recreation hours. The joint PDF is
f
X
Y
(
x
,
y
)
=
c
(
x
+
y
)
f_{XY}(x,y)=c(x+y)
for
0
≤
x
≤
1
0\le x\le1
,
0
≤
y
≤
2
0\le y\le2
, and
0
0
otherwise. Find
21
c
21c
.
Integer answer
easy
3 marks
DECEMBER 01, 2024
DECEMBER 01, 2024
Q29
Let
X
X
represent the total service time for
100
100
customers. Which option is an acceptable approximate model for
X
X
as per the CLT?
Comprehension
easy
2 marks
DECEMBER 01, 2024
DECEMBER 01, 2024
Q30
Using CLT, find the approximate probability that the total service time exceeds
1200
1200
minutes. Enter the answer correct to two decimal places.
Comprehension
medium
2 marks
DECEMBER 01, 2024
DECEMBER 01, 2024
Q31
Find the joint density function
f
X
Y
(
x
,
y
)
f_{XY}(x,y)
.
Comprehension
easy
3 marks
DECEMBER 01, 2024
DECEMBER 01, 2024
Q32
Find
P
(
X
+
Y
<
2
)
P(X+Y<2)
. Enter the answer correct to one decimal place.
Comprehension
medium
3 marks
DECEMBER 01, 2024
DECEMBER 01, 2024
Q33
A survey estimates the proportion of voters supporting a candidate. The true proportion is
0.45
0.45
and a random sample of
500
500
voters is taken. Using the Central Limit Theorem, what is the approximate probability that the sample proportion is between
0.43
0.43
and
0.47
0.47
?
Single correct
medium
3 marks
AUGUST 04, 2024
AUGUST 04, 2024
Q34
If the joint PDF is
f
X
Y
(
x
,
y
)
=
1
/
k
f_{XY}(x,y)=1/k
for
(
x
,
y
)
∈
D
(x,y)\in D
and
0
0
otherwise, find
k
k
correct to two decimal places.
Comprehension
easy
1 marks
AUGUST 04, 2024
AUGUST 04, 2024
Q35
Which option(s) are true?
Comprehension
medium
2 marks
AUGUST 04, 2024
AUGUST 04, 2024
Q36
Find the conditional distribution
f
Y
∣
X
(
y
∣
x
)
f_{Y|X}(y|x)
.
Comprehension
medium
3 marks
AUGUST 04, 2024
AUGUST 04, 2024
Q37
Find
P
(
X
<
1
/
2
∣
Y
=
1
/
2
)
P(X<1/2\mid Y=1/2)
.
Comprehension
easy
2 marks
AUGUST 04, 2024
AUGUST 04, 2024
Q38
What is the expected value of the sample mean time spent on social media?
Comprehension
easy
2 marks
AUGUST 04, 2024
AUGUST 04, 2024
Q39
Using CLT, what is the approximate distribution of the sample mean recovery time?
Comprehension
easy
2 marks
AUGUST 04, 2024
AUGUST 04, 2024
Q40
Using CLT, find the approximate probability that the sample mean recovery time is between
4
4
and
6
6
days. Enter the answer correct to two decimal places.
Comprehension
medium
3 marks
AUGUST 04, 2024
AUGUST 04, 2024
Q41
What is the distribution of
X
X
?
Comprehension
medium
3 marks
AUGUST 04, 2024
AUGUST 04, 2024
Q42
Find
P
(
W
=
1
∣
X
=
−
1
)
P(W=1\mid X=-1)
. Enter the answer correct to two decimal places.
Comprehension
medium
2 marks
AUGUST 04, 2024
AUGUST 04, 2024
Q43
Let
X
1
,
X
2
,
…
,
X
30
X_1, X_2, \ldots, X_{30}
be i.i.d. Bernoulli
(
0.8
)
(0.8)
. Define a new random variable
Y
=
X
1
+
X
2
+
⋯
+
X
30
Y=X_1+X_2+\cdots+X_{30}
. Using the Central Limit Theorem, find the approximate value of
P
(
Y
>
21
)
P(Y>21)
. Enter the answer correct to two decimal places.
Integer answer
medium
3 marks
MARCH 24, 2024
MARCH 24, 2024
Q44
Let
X
X
and
Y
Y
be two continuous random variables with joint PDF
f
X
Y
(
x
,
y
)
=
x
+
c
y
2
f_{XY}(x,y)=x+cy^2
for
0
≤
x
≤
1
0\le x\le 1
and
0
≤
y
≤
1
0\le y\le 1
, and
0
0
otherwise. Find the value of
c
c
. Enter the answer correct to one decimal place.
Integer answer
easy
3 marks
MARCH 24, 2024
MARCH 24, 2024
Q45
Let
X
1
,
X
2
,
…
,
X
100
X_1, X_2, \ldots, X_{100}
be i.i.d. samples with mean
150
150
and variance
100
100
. Find the mean and variance of
X
ˉ
\bar{X}
, where
X
ˉ
=
X
1
+
X
2
+
⋯
+
X
100
100
\bar{X}=\frac{X_1+X_2+\cdots+X_{100}}{100}
is the sample mean.
Single correct
easy
3 marks
MARCH 24, 2024
MARCH 24, 2024
Q46
Find the marginal density of
X
X
.
Comprehension
medium
3 marks
MARCH 24, 2024
MARCH 24, 2024
Q47
What is the value of
E
[
X
]
E[X]
? Enter the answer correct to one decimal place.
Comprehension
easy
2 marks
MARCH 24, 2024
MARCH 24, 2024
Q48
Let a random variable
X
X
denote the total number of students without laptops in the selected sample. Which of the following options is a good model for
X
X
?
Comprehension
easy
2 marks
MARCH 24, 2024
MARCH 24, 2024
Q49
Using the Central Limit Theorem, find an approximate probability that at least
80
80
students in the selected random sample own a laptop. Enter the answer correct to one decimal place.
Comprehension
medium
3 marks
MARCH 24, 2024
MARCH 24, 2024
Q50
Find the value of
k
k
.
Comprehension
easy
2 marks
MARCH 24, 2024
MARCH 24, 2024
Q51
What is the value of
P
(
X
<
1
2
,
Y
<
1
2
)
P(X<\frac12, Y<\frac12)
?
Comprehension
medium
3 marks
MARCH 24, 2024
MARCH 24, 2024
Q52
Let
(
X
,
Y
)
∼
U
n
i
f
o
r
m
(
D
)
(X,Y)\sim \mathrm{Uniform}(D)
, where
D
=
{
(
x
,
y
)
:
x
+
y
<
3
,
x
>
0
,
y
>
0
}
D=\{(x,y):x+y<3,\ x>0,\ y>0\}
. What is the marginal density function of
f
X
(
x
)
f_X(x)
?
Single correct
medium
3 marks
DECEMBER 03, 2024
DECEMBER 03, 2024
Q53
Suppose the moment generating function of a random variable
X
X
is given by
M
X
(
t
)
=
e
2
t
2
M_X(t)=e^{2t^2}
. Let
X
1
,
X
2
,
X
3
,
X
4
X_1,X_2,X_3,X_4
be i.i.d. samples with distribution
X
X
and
Y
=
X
1
+
X
2
+
X
3
+
X
4
Y=X_1+X_2+X_3+X_4
. Which of the following options is true?
Single correct
easy
3 marks
DECEMBER 03, 2024
DECEMBER 03, 2024
Q54
Are
X
X
and
Y
Y
independent?
Comprehension
easy
2 marks
DECEMBER 03, 2024
DECEMBER 03, 2024
Q55
Find the value of
P
(
X
<
Y
)
P(X<Y)
. Enter the answer correct to one decimal place.
Comprehension
easy
3 marks
DECEMBER 03, 2024
DECEMBER 03, 2024
Q56
Using Central Limit theorem, find the approximate probability that there are more than
53
53
errors in a certain data file. Enter the answer correct to two decimal places.
Comprehension
medium
3 marks
DECEMBER 03, 2024
DECEMBER 03, 2024
Q57
Find the joint density function
f
X
Y
(
x
,
y
)
f_{XY}(x,y)
.
Comprehension
easy
1 marks
AUGUST 06, 2023
AUGUST 06, 2023
Q58
Find
P
(
∣
X
−
Y
∣
<
1
)
P(|X-Y|<1)
. Enter the answer correct to two decimal places.
Comprehension
medium
4 marks
AUGUST 06, 2023
AUGUST 06, 2023
Q59
Find the value of
c
c
. Enter the answer correct to two decimal places.
Comprehension
easy
2 marks
AUGUST 06, 2023
AUGUST 06, 2023
Q60
What is the probability that the pressure change during the chemical process is more than
0.5
0.5
, given that the temperature change is equal to
0.5
0.5
? Enter the answer correct to two decimal places.
Comprehension
medium
3 marks
AUGUST 06, 2023
AUGUST 06, 2023
Q61
Let a random variable
X
X
denote the total number of children who have normal eye-sight in the selected sample. Which of the following is true?
Comprehension
easy
2 marks
AUGUST 06, 2023
AUGUST 06, 2023
Q62
Using the Central Limit Theorem, find the approximate probability that in a random sample of
200
200
selected children at least
20
20
will have defective eye-sight. Enter the answer correct to 1 decimal place.
Comprehension
medium
3 marks
AUGUST 06, 2023
AUGUST 06, 2023
Q63
Let
(
X
,
Y
)
∼
U
n
i
f
o
r
m
(
D
)
(X,Y)\sim \mathrm{Uniform}(D)
, where
D
=
{
(
x
,
y
)
:
2
<
x
+
y
<
4
,
x
>
0
,
y
>
0
}
D=\{(x,y):2<x+y<4,\ x>0,\ y>0\}
. Find
P
(
Y
<
2
X
)
P(Y<2X)
.
Single correct
medium
3 marks
APRIL 02, 2023
APRIL 02, 2023
Q64
Find the PDF of the marks of a candidate chosen uniformly at random.
Comprehension
medium
3 marks
APRIL 02, 2023
APRIL 02, 2023
Q65
If a randomly selected candidate got
60
60
marks, what is the probability that the selected candidate is a boy?
Comprehension
medium
2 marks
APRIL 02, 2023
APRIL 02, 2023
Q66
Find the value of
c
c
. Enter the answer correct to one decimal place.
Comprehension
medium
2 marks
APRIL 02, 2023
APRIL 02, 2023
Q67
Find the probability that the amount of petrol sold in a given week is less than half the amount stocked in that week. Enter the answer correct to two decimal places.
Comprehension
medium
2 marks
APRIL 02, 2023
APRIL 02, 2023
Q68
Suppose a sample of
20
20
bottles is selected for a quality inspection. Let
X
X
denote the total number of bottles that are of bad quality in the selected sample. Which of the following is true?
Comprehension
easy
2 marks
APRIL 02, 2023
APRIL 02, 2023
Q69
Using the Central Limit Theorem, find the approximate probability that a machine will produce more than
370
370
bottles that are of good quality on a particular day. Enter the answer correct to two decimal places.
Comprehension
medium
3 marks
APRIL 02, 2023
APRIL 02, 2023
Q70
Which of the following statements are true?
Comprehension
medium
3 marks
NOVEMBER 20, 2022
NOVEMBER 20, 2022
Q71
Are
X
X
and
Y
Y
independent?
Comprehension
easy
1 marks
NOVEMBER 20, 2022
NOVEMBER 20, 2022
Q72
Suppose iron rods are manufactured with a mean weight of
10
10
kg and a standard deviation of
0.4
0.4
kg. How does the variance of the sample mean change when the sample size is increased from
25
25
to
64
64
?
Single correct
easy
3 marks
NOVEMBER 20, 2022
NOVEMBER 20, 2022
Q73
Suppose
Y
Y
represents the total number of bits without an error in a certain data file. Which of the following is true?
Comprehension
easy
2 marks
NOVEMBER 20, 2022
NOVEMBER 20, 2022
Q74
Using the Central Limit Theorem, find the approximate probability that there are more than
45
45
errors in a certain data file. Enter the answer correct to two decimal places.
Comprehension
medium
3 marks
NOVEMBER 20, 2022
NOVEMBER 20, 2022
Q75
Find the value of
c
c
.
Comprehension
medium
2 marks
NOVEMBER 20, 2022
NOVEMBER 20, 2022
Q76
Find the probability that the stock price of A will be higher than that of B. Enter the answer correct to two decimal places.
Comprehension
medium
3 marks
NOVEMBER 20, 2022
NOVEMBER 20, 2022
Q77
Let
X
1
,
X
2
,
…
,
X
30
X_1,X_2,\ldots,X_{30}
be i.i.d. Poisson
(
2
)
(2)
, and let
Y
=
∑
i
=
1
30
X
i
Y=\sum_{i=1}^{30}X_i
. Using the Central Limit Theorem, find the value of
P
(
Y
>
20
)
P(Y>20)
.
Single correct
medium
3 marks
JULY 10, 2022
JULY 10, 2022
Q78
Suppose random variables
X
X
and
Y
Y
are uniformly distributed over the region
D
=
(
[
−
1
,
0
]
×
[
0
,
1
]
)
∪
(
[
0
,
2
]
×
[
−
2
,
0
]
)
D=([-1,0]\times[0,1])\cup([0,2]\times[-2,0])
. Choose the correct options from the following.
Multiple correct
medium
3 marks
JULY 10, 2022
JULY 10, 2022
Q79
Calculate
P
(
0
<
X
<
1
/
2
,
1
/
4
<
Y
<
1
/
2
)
P(0<X<1/2,\ 1/4<Y<1/2)
. Enter the answer correct to three decimal places.
Comprehension
easy
1 marks
JULY 10, 2022
JULY 10, 2022
Q80
Find
P
(
0
<
X
<
1
/
2
)
P(0<X<1/2)
. Enter the answer correct to one decimal place.
Comprehension
easy
1 marks
JULY 10, 2022
JULY 10, 2022
Q81
Find
P
(
X
<
2
Y
)
P(X<2Y)
. Enter the answer correct to two decimal places.
Comprehension
medium
2 marks
JULY 10, 2022
JULY 10, 2022
Q82
Find the minimum value of
n
n
such that the probability that the sample mean
X
ˉ
\bar X
is within
0.2
0.2
of the distribution mean is at least
0.9
0.9
using the Weak Law of Large Numbers.
Comprehension
medium
3 marks
JULY 10, 2022
JULY 10, 2022
Q83
Find the distribution of runs of a randomly chosen player.
Comprehension
medium
3 marks
JULY 10, 2022
JULY 10, 2022
Showing 83 questions.