Welcome to the live session of Statistics & Average Part II. You can watch the entire session by playing the embedded video. The questions discussed on November 3, 2017 during the live session are listed below the embedded video. The video link next to each question will take you to the start of the part of the video where that specific question is discussed. Click the video embedded below to watch the entire session.

Questions Discussed

Standard Deviation

1. Consider the following set of numbers: 50, 40, 10, 20, 60, 30, 70, 90, 80. How many of these observations lie within one standard deviation of the mean?

   • Correct Answer
   • LOD: Easy
   • Video Solution

2. If the standard deviation of 4 positive numbers p, q, r, and s is d, what is the standard deviation of (2p – 2), (2q – 2), (2r – 2) and (2s – 2)?

   • Correct Answer
   • LOD: Easy
   • Video Solution

Data Sufficiency Questions

Easy Questions

1. What is the median of integers a, b, and c?

   1. ab = 0
   2. bc = 0
   • Correct Answer
   • LOD: Easy
   • Video Solution

2. If ab = c, what is the median of a, b, and c?

   1. a = 1
   2. c = 1
   • Correct Answer
   • LOD: Easy
   • Video Solution

3. If Set S = {x, x, y, z} what is the standard deviation of S?

   1. x = y = z
   2. x × y × z = 0
   • Correct Answer
   • LOD: Easy
   • Video Solution

4. A stationary car starts moving, and is accelerating constantly. Will it average higher than 60 km/h over a 4 km journey?

   1. The car travels the first 1 km in 1:30 min.
   2. The car travels the first 2 km in 2 min.
   • Correct Answer
   • LOD: Easy
   • Video Solution

5. What is the standard deviation of three positive integers, a, b, and c?

   1. a - b = b - c
   2. a = c
   • Correct Answer
   • LOD: Easy
   • Video Solution

Medium Difficulty Questions

1. a, b, and c are three positive integers such that abc = 12. What is the standard deviation of a, b and c?

   1. The median of a, b, and c is equal to the range of a, b, and c.
   2. The median of a, b, and c is less than the range of a, b, and c.
   • Correct Answer
   • LOD: Medium
   • Video Solution

2. Is 'b' the median of three numbers, a, b and c?

   1. |a – b| = |b – c|
   2. b > c
   • Correct Answer
   • LOD: Medium
   • Video Solution