Why Is the Value '2' Used in Calculating Coin Variance?

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The discussion centers on calculating the mean and variance of a bag of coins containing 1 cent and 5 cent coins in a 1:3 ratio. The confusion arises regarding the use of the value '2' in the calculations, with some participants questioning why '5' isn't used instead, as it directly represents the 5 cent coins. One participant suggests there may be a typo in the sample answer, proposing that the correct mean calculation should yield 4 cents. The importance of understanding the ratio and its impact on the mean and variance is emphasized. Clarification on the use of values in statistical calculations is crucial for accurate results.
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Homework Statement



A bag contains a large number of coins comprises of 1 cent and 5 cents coins in the ration of 1:3

find the man and variance of the values of coins..
i have attached the sample ans here. i don't understand why the value of '2' is used?? why not '5' ...for me '5' represent 5 cents.

Homework Equations

The Attempt at a Solution

 

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werson9339 said:

Homework Statement



A bag contains a large number of coins comprises of 1 cent and 5 cents coins in the ration of 1:3

find the man and variance of the values of coins..
i have attached the sample ans here. i don't understand why the value of '2' is used?? why not '5' ...for me '5' represent 5 cents.

Homework Equations

The Attempt at a Solution

I think there is a typo in the sample answer. The mean should be 1*1/4 + 5*3/4 = 1/4 + 15/14 = 16/4 = 4 (cents).
 
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Thread 'Family of lines that are at a distance of 5 from the origin'

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