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

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?

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)?
Data Sufficiency Questions
Easy Questions
What is the median of integers a, b, and c?
 ab = 0
 bc = 0
If ab = c, what is the median of a, b, and c?
 a = 1
 c = 1
If Set S = {x, x, y, z} what is the standard deviation of S?
 x = y = z
 x × y × z = 0
A stationary car starts moving, and is accelerating constantly. Will it average higher than 60 km/h over a 4 km journey?
 The car travels the first 1 km in 1:30 min.
 The car travels the first 2 km in 2 min.
What is the standard deviation of three positive integers, a, b, and c?
 a  b = b  c
 a = c
Medium Difficulty Questions
a, b, and c are three positive integers such that abc = 12. What is the standard deviation of a, b and c?
 The median of a, b, and c is equal to the range of a, b, and c.
 The median of a, b, and c is less than the range of a, b, and c.
Is 'b' the median of three numbers, a, b and c?
 a – b = b – c
 b > c