Exam 1

1. Metainformation

   Tag	Value
   file	Probability_uva-variance-1079-en_uva-variance-1079-en
   name	uva-variance-1079-en
   section	Probability/Elementary Probability/Random variables/Variance
   type	schoice
   solution	FALSE, FALSE, FALSE, TRUE
   Type	Conceptual, Calculation
   Language	English
   Level	Statistical Literacy
   IRT-Difficulty	3.804
   p-value	0.1552

   Question

   If you roll a dice, the outcome will be 1, 2, 3, 4, 5 or 6. Below is a probability distribution for the sum of two dice that were rolled. Calculate the mean and variance from this distribution:‖
   

   ————————— —— —— —— —— —— —— —— —— —— —— —— Sum of two dice 2 3 4 5 6 7 8 9 10 11 12 Odds 1/36 2/36 3/36 4/36 5/36 6/36 5/36 4/36 3/36 2/36 1/36 ————————— —— —— —— —— —— —— —— —— —— —— ——

   
   
   1. FALSE: Μ = 3.5 and σ2 = 2.917.
   2. FALSE: Μ = 3.5 and σ2 = 5.834.
   3. FALSE: Μ = 7 and σ2 = 2.917.
   4. TRUE: Μ = 7 and σ2 = 5.834.
   
   
   1. Μ = 3.5 and σ2 = 2.917…: Incorrect
   2. Μ = 3.5 and σ2 = 5.834…: Incorrect
   3. Μ = 7 and σ2 = 2.917…: Incorrect
   4. Μ = 7 and σ2 = 5.834…: Correct