Exam 1

1. Metainformation

   Tag	Value
   file	Descriptive-statistics_uva-variance-258-en_uva-variance-258-en
   name	uva-variance-258-en
   section	Descriptive statistics/Summary Statistics/Measures of Spread/Variance
   type	schoice
   solution	FALSE, FALSE, TRUE, FALSE
   Type	Conceptual
   Language	English
   Level	Statistical Literacy
   IRT-Difficulty	3.441
   p-value	0.2254

   Question

   If I perform 2 independent draws X₁ and X₂ from the same distribution (with variance = 5), then for the variances of 2X₁ and X₁ + X₂:

   
   
   1. FALSE: Var(2X1) < var(X1 + X2)
   2. FALSE: Var(2X1) = var(X1 + X2)
   3. TRUE: Var(2X1) > var(X1 + X2)
   4. FALSE: Var(2X1) and var(X1 + X2) are not comparable
   
   
   1. Var(2X1) < var(X1 + X2): Incorrect
   2. Var(2X1) = var(X1 + X2): Incorrect
   3. Var(2X1) > var(X1 + X2): Correct
   4. Var(2X1) and var(X1 + X2) are not comparable: Incorrect