How to practice Probability and Statistics

Attempt a question, record the concept and assumptions, then check the available answer. Rework mistakes after revising the relevant concepts. Topic tags can overlap; review the question context.

Questions 1–10 of 16. Imported answers require independent review unless marked reviewed.

Topic practice 16 questionsPage 1 of 2

Question 64

Open question
EENAT2 marksNeeds review
Let X and Y be two real-valued random variables with E(X) = 1, E(Y) = 2, E(X²) = 4, E(Y²) = 9, and E(XY) = 0.9, where E denotes the expectation operator.
The value of α that minimizes E((X − αY)²) is __________ (Round off to one decimal place)

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Question 15

Open question
EEMCQ1 markNeeds review
Consider discrete random variables

and

with probabilities as follows:




Given

, the expected value of

is
Your answerChoose one option.

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Question 36

Open question
EEMCQ2 marksNeeds review
Let

and

be continuous random variables with probability density functions

and

, respectively. Further, let

and

Which one of the following options is correct?
Your answerChoose one option.

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Question 29

Open question
EEMSQ1 markNeeds review
Let

be a discrete random variable that is uniformly distributed over the set

. Which of the following random variables is/are uniformly distributed?
Your answerSelect all correct options. You can choose more than one.

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Question 25

Open question
EEMCQ1 markNeeds review
One million random numbers are generated from a statistically stationary process with a Gaussian distribution with mean zero and standard deviation

. The

is estimated by randomly drawing out 10,000 numbers of samples (

). The estimates

are computed in the following two ways.

Which of the following statements is true?
Your answerChoose one option.

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Question 35

Open question
EENAT1 markNeeds review
Three points in the x-y plane are (-1, 0.8), (0, 2.2) and (1, 2.8). The value of the slope of the best fit straight line in the least square sense is __________ (Round off to 2 decimal places).

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Question 45

Open question
EENAT2 marksNeeds review
The expected number of trials for first occurrence of a “head” in a biased coin is known to be 4. The probability of first occurrence of a “head” in the second trial is __________ (Round off to 3 decimal places).

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Question 7

Open question
GAMCQ2 marksNeeds review
There are two identical dice with a single letter on each of the faces. The following six letters: Q, R, S, T, U, and V, one on each of the faces. Any of the six outcomes are equally likely.
The two dice are thrown once independently at random.
What is the probability that the outcomes on the dice were composed only of any combination of the following possible outcomes: Q, U and V?
Your answerChoose one option.

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Question 54

Open question
EENAT2 marksNeeds review
Let the probability density function of a random variable

be given as

The value of ‘a’ is ________.

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Question 8

Open question
GAMCQ2 marksNeeds review
Let

be a continuous random variable denoting the temperature measured. The range of temperature is [0, 100] degree Celsius and let the probability density function of

be

for

. The mean of

is ____
Your answerChoose one option.

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