statistic
posted by carol .
Let's assume there are 3 people in Room A and another 3 people in Room B. The ages of the people in Room A are 25, 25, and 25. The ages of the people in Room B are: 10, 25, and 40. The mean of the ages in both rooms is 25. Does that mean that both room have populations that are equivalent? Is it fair to say that the number 25 is truly an indication of how old the people in the two rooms are? Well, not exactly... There is NO dispersion in the ages of the people in Room A (since everybody is the same age...), but there is large dispersion in Room B.
The standard deviation of the ages in Room A is zero; the standard deviation of the ages in Room B is 12.25. So, when we say that for Room B the mean is 25 and the standard deviation is 12.25, we get a better picture of the age distribution in the room. Standard deviation is a measure of the "spread" in the data.
Also, how did I get 12.25? How was it calculated?

Standard Deviation = SQRT [ {sqr(1025) + sqr (2525) + sqr (4025)}/3 ]
Respond to this Question
Similar Questions

Physics
In a "Rotorride" at a carnival, people are rotated in a cylindrically walled "room." The radius of the room is 5.5 m, The coefficient of static friction is μ=0.1. What is the minimum rotation frequency such that the people will … 
English
Could anyone suggest a food that could go in Room 101. Room 101 is a room where you put all the foods you hate. I have been assigned to write a persuasive text on why i want this food to be put in room 101 and why. Kindly suggest a … 
statistics
If 20% of the people in a community use the emergency room at a hospital in one year, find the probabilities for a sample of 10 people, a.At the most three use the emergency room. b.Exactly three use the emergency room c.At least five … 
math
one third of the people in a convention room are seated in threefourths of the chairs. THe rest of the people in the room decide to stand. If there are 8 empty chairs, how many people are standing? 
Math
It is recommended that there be at least 7 square feet of work space for every person in a conference room. A certain conference room is 13' by 16'. Find the maximum number of people the room can accommodate. 
math
each table in a banquet room seats 8 people. The room can seat no more than 360 people. Write and solve an inequality to represent the number of tables in the banquet room 
Physics
In a "Rotorride" at a carnival, people are rotated in a cylindrically walled "room." The radius of the room is 4.0 m, The coefficient of static friction is μ=0.13. What is the minimum rotation frequency such that the people will … 
Philosphy  Dream Interpreations
I recently just had a dream when I was alone in my room enjoying myself and suddenly about 45 to what I perceived as venomous snakes, each with a vivid and distinct coloring design, appeared from the trashcan in the room and start … 
math
Which strategies can be used to solve this problem? 
Algebra
Can you PLEASE help me with this Algebra problem: In a hotel conference room, the number of chairs is 47 more than the number of people currently in the room. The total number of legs currently in this room is 938. What is the sum …