Hmmm....I'll post a more conservative guess of $1,312.94

$1436.72

I'll guess there is $1850

Ok due to some anal people asking, here are the measurements. lol

23" Tall
bottom base has a radius of 3.5"

I am going to take the lowend and guess $761.42.

I'll guess

$532.52

Humm, these lower guesses... I'm waiting for someone to guess $1. lol

How about 512.64

If the piggybank were a perfect cylinder, it's volume would be pi*r^2*h, or 3.14*(3.5")^2*23" = 884.7 cubic inches.

This volume is too big, however, because the piggybank tapers and forms a neck. The neck appears to be about 1/3 the bank's height, so I will estimate the volume of the piggybank to be (3.14*(3.5")^2*15.3") + 3/4 * (3.14*(3.5")^2*7.7") = 810.6 cubic inches.

It is difficult to know exactly how much money fits within a cubic inch, but I measure on a standard ruler that at max, 8 quarters can fit in a 1"x1"x1" space.

The other coins are smaller, so I am going to allow 1.8 dimes, 1.2 nickels, 1.5 pennies as rough estimates for the number of repective coins that take up the same space amount of space as a quarter. (These are the closest measurement comparisons I can obtain for the size differences between different coins.)

Our maximum value, then for a cubic inch is $2 (8 quarters) and our minimum value for a cubic inch is 12 cents (12 pennies). That's an average of $1.06 per cubic inch relying completely on the size of the coins.

I believe this number ($1.06 per cubic inch) is a little inaccurate, however, because it assumes that the piggybank contains an equal number of each coin type, which will certainly not be the case. On any given transaction, a person will rarely (or never) receive more than 3 quarters, more than 2 dimes, more than 1 nickel, or more than 4 pennies.

A buyer will not receive the maximum allowed number of a certain coin type on every transaction, so we can't assume that the ratio of quarters to dimes to nickels to pennies will be an exact 3:2:1:4, but we CAN assume that the piggybank will contain more pennies than quarters, more quarters than dimes, and more dimes than nickels.

Assuming that change for transactions result in an equally distibuted range from 1 cent to 99 cents (a fair assumption), a proper ratio of coins to each other can be determined by figuring out exactly how many of each coin a cashier would need after making 99 transactions where each transaction amount (1 to 99 cents) was represented exactly once:

For the above experiment:

150 quarters are needed (1 for each transaction between 25 and 49 cents, 2 for each transaction between 50 and 74 cents, and 3 for each transaction between 75 and 99 cents; 1*25 + 2*25 + 3*25 = 150),

80 dimes are are needed (1 for each transaction between the ranges 10 to 19, 35 to 44, 60 to 69, and 85 to 94 and 2 for each transaction between the ranges 20 to 24, 45 to 49, 70 to 74, and 95 to 99; 4*10 + 2*5*4 = 80),

40 nickels are needed (1 for each transaction between 5 to 9, 15 to 19, ..., 95 to 99; 10*4 = 40),

and 200 pennies are needed (1 penny for every number that ends in 1 or 6, 2 pennies for every number that ends in 2 or 7, 3 pennies for every number that ends in 3 or 8, and 4 pennies for every number that ends in 4 or 9; 1*20 + 2*20 + 3*20 + 4* 20 = 400).

In summary a cashier needs 150 quarters, 80 dimes, 40 nickels, and 200 pennies for every transaction from 1 to 99 cents. This equates to a 15:8:4:20 ratio of quarters to dimes to nickels to pennies, meaning that every random handful of $4.95 in change can be expected to consist of 15 quarters, 8 dimes, 4 nickels, and 20 pennies.

From my numbers earlier (8 quarters per cubic inch, etc.), 15 quarters can fit into 1.875 cubic inches, 8 dimes can fit into .555 cubic inches, 4 nickels can fit into .416 cubic inches, and 20 pennies can fit into 1.666 cubic inches. Therefore, $4.95 should on average take up 4.512 cubic inches, which correlates to $1.097 per cubic inch (almost 3 cents higher than the original $1.06 per cubic inch).

So, assuming 810.6 cubic inches is a good guess for the volume of the piggybank (maybe Eric will post more measurements concerning the height and radius of the neck at different points), my estimated guess is $1.097 * 810.6 = $889.23

I love it. He went the distance of accounting for the volume and average coin size, then went to the extra mile to figure out how much would be calcuated from average transactions.

I like my guess. Who cares if my hopes come down crashing.

My Guess: $620.64 & a bag of chips.

I made a rough guess that the bottom 15" was a cylinder, and the top 8" had half the volumne of a cylinder. Then I calculated the volumn of each section, and used the height and radius of a penny, nickel, dime, and quarter to approx how many would fit into that volumne with a non-perfect stacking method (I assumed each coin was a square to account for the inevitible gaps between coins, and that there were no 50 cent or dollar coins.

That gave me these totals per coin type:
Quarter: $1,130
Dime: $1,074
Nickel: $265
Penny: $128.3

I had intially used a simple 1:2:3:4 ratio between the coins, but after just reading Riley's post I like his 15:8:4:20 ratio better and recalced with that.

So it gives me $620.64 total. Seems kind of low, but I'll low ball you. =)

And the winner from a previous post about me emptying my coin jar is...  Riley.  He used a...

And the winner is...

Riley for his non-best-guess of using math to figure it out.

Total: $851.51
http://eduncan911.com/blogs/eduncan911/archive/2005/11/06/216.aspx


If we are going by the "Price is Right" rules, Ken is the winner.

Eric,

I know this blog is old, but came across it when I was looking to guess the same thing with a 5 gallon jug I'd been saving in for about 10-12 years.  I used Riley's formula and figured out the jar was ~1155 Cubic inches * 1.097 = $1,267.04.  Cashed it in today and it was $1,311.37 not including a few pesos that got dropped in there, so his calculations are pretty close.  I originally thought it was about $600, so it looks like I'm getting a bigger flat screen.  

Hahaha.  Excellent Beach!

I'll let Riley know.