Tag: random variable and mathematical expectation

Quizzes (3) Questions (42)

Questions Related to random variable and mathematical expectation

Multiple choice business mathematics and statistics random variable and mathematical expectation discrete and continuous data random variable random variable and its types

Sizes of shoe are which types of variables?

  1. discrete

  2. random

  3. continous

  4. nominal
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

There are two types of variables. Discrete and continuous. 

To explain by example, the set of real numbers is continuous, between any two distinct real numbers there exist infinite real numbers. Between 1.2 and 1.3 there exists 1.24 and so many more. 
The set of natural numbers on the other hand, constitutes a discrete sample space. 
Due to the limitations posed by manufacturing tools, we can only produce shoes of varying sizes in discrete steps.

Multiple choice business mathematics and statistics random variable and mathematical expectation discrete and continuous data random variable random variable and its types

The mean of discrete obervations $y _1, y _2$ , ................ , $y _n$ is given by

  1. $\displaystyle \frac{\sum _{i=1}^{n} y _i}{n}$
  2. $\displaystyle \frac{\sum _{i=1}^{n} y _i}{\sum _{i=1}^{n}i}$
  3. $\displaystyle \frac{\sum _{i=1}^{n} y _i f _i}{n}$
  4. $\displaystyle \frac{\sum _{i=1}^{n} y _i f _i}{\sum _{i=1}^{n}y _if _i}$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Mean of terms = $\dfrac{Sum}{number}$


Therefore, Mean = $\displaystyle \dfrac{\sum _{i=1}^{n} y _i}{n}$

Multiple choice business mathematics and statistics random variable and mathematical expectation discrete and continuous data random variable random variable and its types

Number of patients in a hospital are discrete variable


If true then enter $1$ and if false then enter $0$

  1. $1$
  2. $0$

  3. can't determine

  4. None of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A discrete variable is one that can only take specific, countable values. Since you cannot have a fraction of a patient, the number of patients is a discrete variable.

Multiple choice business mathematics and statistics random variable and mathematical expectation discrete and continuous data random variable random variable and its types

Sizes of shoes are discrete variables,

If true then enter $1$ and if false then enter $0$

  1. Varies from case to case
  2. $0$
  3. $1$

  4. None of these
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Size of a shoe can have values only in natural numbers. Hence, it is a discrete variable.

Hence, option (C) is correct

Multiple choice business mathematics and statistics random variable and mathematical expectation discrete and continuous data random variable random variable and its types

State, which of the following variables are continuous and which are discrete :


Daily temperature of a city is continuous
If true then enter $1$ and if false then enter $0$

  1. Can't determine
  2. $0$
  3. $1$

  4. None of these
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Temperature of a city can have any value including integers and rational numbers. Hence, it is a continuous variable.