Expression in terms of X for the variance

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Discussion Overview

The discussion revolves around finding an expression for the variance of a set of numbers, specifically 9, 4, x, and 3, expressed in the form of ax² + bx + c. Participants explore the approach to calculating variance without reaching a definitive solution.

Discussion Character

  • Homework-related
  • Mathematical reasoning

Main Points Raised

  • One participant requests assistance in finding an expression for variance, indicating uncertainty about how to approach the problem.
  • Another participant suggests using the statistical formula for variance, which involves the average value and the individual data points.
  • A further inquiry is made regarding the calculation of the average value (xbar) for the given numbers.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the method to calculate the variance, and multiple approaches are suggested without resolution.

Contextual Notes

There are missing assumptions regarding the calculation steps and the specific application of the variance formula to the set of numbers provided.

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1. 'Find an expression in terms of x for the variance of: 9,4,x,3'
Give your answer in the form of ax^2 + bx + c

I would usually give you some information of how I could possibly tackle this question but unfortunately I have no idea. Could someone shed some light? Thanks
 
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Well, given four numbers, 9,4, BLOING,3, how would you normally calculate the variance related to this set of numbers?
 
well I'd use the statistical formula for variance
Variance = Sum of (x - xbar)^2 / n
 
So, what is the average value, xbar, with the numbers that have been given you?
 

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