Transforming Random Variables

Let X be the salary of a randomly selected McDonald's employee.

Which of the following represents the total salary of two randomly selected employees.

• $X_1+X_2$

• $2\cdot X$

• $X+2$

• $\frac{X}{2}$

Let X be the salary of a randomly selected McDonald's employee.

Suppose each employee has received a raise of $2 per hour. Which of the following represents the new salary of a randomly selected employee?

• $2\cdot X$

• $X+2$

• $X_1+X_2$

• $\frac{X}{2}$

Tags

CCSS.HSA.CED.A.1

CCSS.HSA.SSE.A.1

Let X be the score a student receives on their first exam and Y be the score they receive on their second exam.

Which of the following represents the student's average score?

• $X+Y$

• $\frac{1}{2}\left(X+Y\right)$

• $X-Y$

• $\frac{2X+2Y}{2}$

Tags

CCSS.HSA.SSE.A.2

CCSS.HSA.SSE.B.3

Let X be the number of free throws a randomly selected fan can make in 60 seconds.

If that fan wins $100 for each free-throw they make, which of the following represents that fan's winnings?

• $100\cdot X$

• $X_1+X_2+X_3+...+X_{100}$

• $100+X$

• $X^{100}$

Tags

CCSS.HSS.MD.A.2

CCSS.HSS.MD.A.3

CCSS.HSS.MD.B.5

Which of the following is equivalent to:

 $Var\left(X-Y\right)$  

•  $Var\left(X\right)-Var\left(Y\right)$  

•  $Var\left(X\right)+Var\left(Y\right)$  

•  $Y\cdot Var\left(X\right)+X\cdot Var\left(Y\right)$  

•  $\sqrt{X-Y}$  

Which of the following is equivalent to:

 $Var\left(5\cdot X\right)$  

•  $5\cdot Var\left(X\right)$  

•  $5\cdot X^2$  

•  $5^2\cdot Var\left(X\right)$  

•  $25^2\cdot Var\left(X\right)$  

Which of the following is equivalent to:

 $Var\left(X+36\right)$  

•  $6\cdot Var\left(X\right)$  

•  $36+Var\left(X\right)$  

•  $6+Var\left(X\right)$  

•  $Var\left(X\right)$  

Tags

CCSS.HSS.ID.A.3

CCSS.HSS.ID.A.4