Well, using existing data, algebra (yes it does have a purpose students) and several Hollywood Reporter sales charts; I have calculated that Serenity sold between 1,104,840 and 1,605,348 units for the week of December 20-25th, its first week. If you would just like to accept that number, then ignore all that follows. However, if you would to see how I got that number, prepare to spend a good deal of time reading the work...
Abbreviations:
HR = Hollywood Reporter
FF = Fantastic Four
FB = Four Brothers
40YOV = 40 Year Old Virgin
MAX = Maximum
MIN = Minimum
Facts:
-According to HR, FF sold enough copies its first week to be ranked #34 best seller of the year
-The following week, the first week of 40YOV's release, the 40YOV was reported to have sold 3.7 million and was ranked the #35 best seller of the year
-Therefore FF sold at least 3.7 million units its first week, to avoid speculation, we will say FF sold 3.7 million units its first week.
-Using the relative sales index of the HW charts and the 3.7 million units sold press release of the 40YOV, we can figure out the units sold for the top 10 on the HR chart during the week of December 13th to 19th.
December 13th to 19th:
Rank/Title/....Sales Index/(approx. sales totals)/Rank YTD
1 The 40-Year-Old Virgin ...100.0.... 3,700,000 -- 35
2 Fantastic Four ................39.5..... 1,461,500 -- 23
3 The Polar Express ..........29.3...... 1,084,100
4 Madagascar ...................28.0...... 1,036,000
5 Mr. & Mrs. Smith ............24.6..........910,200
6 The Dukes of Hazzard ....24.3......... 899,100
7 March of the Penguins ....23.7......... 876,900
8 Cinderella Man ...............21.5......... 795,500
9 The Island .....................21.5......... 795,500
10 Star Wars: Episode III ..17.3......... 640,100
-We then calculate the total sales for FF up the 2nd week by adding the 3.7 mil estimate from the first week, to the 1,461,500 extrapolated data from the 2nd week. 3.7 mil + 3.7 mil (.395) = 5,161,500.
-This brings us to the week of Serenity's release.
Dec 20th - 25th
Rank/Title/............../Sales Index/Rank YTD
1 Four Brothers................ 100.0 -- 68
2 The 40-Year-Old Virgin.... 97.2 -- 21
3 The Polar Express........... 56.0
4 Serenity......................... 55.8 -- 100+
5 Madagascar.................... 54.2
6 Brothers Grim................. 51.2
7 March of the Penguins...... 49.7
8 Fantastic Four................. 46.4 -- 20
9 Must Love Dogs.............. 45.9
10 Mr. and Mrs. Smith........ 43.9
-Unfortunately, there were no press releases for Four Brothers numbers so we are going to have to do some ugly algebra to get approximate sales for Four Brothers, which would then give us the serenity first week numbers.
-One fact that is in our favor is that sales rank for the year for 40YOV is #21 and and the year rank for FF is #20, very close. Therefore, if we add the total sales for FF as of Dec. 19th to FF sales from Dec. 20th to 25th this total would be slightly larger than the total sales for 40YOV as of Dec. 19th added to the 40YOV sales from Dec. 20th to 25th.
-Follow me here, the relative sales index for FF is 46.4% and 97.2% for the 40YOV and taking the information in the above entry we end up with an equation:
Clean equation
5,161,500 + .464x > 3,700,00 + .972x
Same equation with elements labeled
5,161,500(FF total sales from 1st two weeks) + .464x(FF sales for the third week) > 3,700,00(40YOV total sales from 1st week) + .972x(40YOV sales for the 2nd week)
-Solving for X yields the MAX possible sales for FB in its first week:
5,161,500 + .464x > 3,700,00 + .972x
-3,700,000............-3,700,000
1,461,500 + .464x > .972x
-.464x...................-.464x
1,461,500 > .508x
/.508......../.508
2,876,968.5 > x
-Therefore, based on historical data, FB could not have sold more than 2,876,968.5 units its first week, so the MAX sales for FB is 2,876,968.5
-Now that we have the MAX sales for FB, we can figure out the MAX totals sales for 40YOV as of its 2nd week of release.
-We take the 40YOV half of the above equation and plug in the numbers:
MAX 40YOV total sales = 3,700,000 + .972(2,876,968.5) = 6,496,413.4 MAX units
-To figure out the MIN total sales for 40YOV as of its 2nd week of release, we will look at the YTD rank. The previous week, FF was ranked #23 with total sales of 5,161,500. This week, the 40YOV is ranked #21 so the total sales as of the 2nd week of release must be greater than 5,161,500. So the MIN total sales for 40YOV as of its 2nd week of release is 5,161,500.
To Summarize 6,496,413.4 units > 40YOV sales as of 2nd week > 5,161,500 units
-Now onto Four Brothers :lol:, as you can see, at the top of the previous paragraph we figured out the MAX possible sales for FB in its 1st week of release, 2,876,968.5.
-To figure out the MIN possible sales for FB in its 1st week of release we will use another ugly algebra equation. This equation is designed to once again solve for X which is the actual total for FB sales: 40YOV unit sales as of Dec. 19th added to the 40YOV sales from Dec. 20th to 25th is greater than the MIN total sales for 40YOV as of its 2nd week of release.
Clean Equation
3,700,00 + .972x > 5,161,500
Same equation with elements labeled
3,700,00(40YOV total sales from 1st week) + .972x(40YOV sales for the 2nd week) > 5,161,500(MIN total sales for 40YOV as of its 2nd week)
-Solving for X yields the MIN possible sales for FB in its first week:
3,700,00 + .972x > 5,161,500
-3,700,000...........-3,700,000
.972x > 1,461,500
/.972..../.972
x > 1,503,600.8
-So the MIN possible sales for FB in its first week is 1,503,600.8 units.
To Summarize 2,876,968.5 units > FB sales the 1st week > 1,503,600.8 units
-Ok folks, we're in the home stretch, time to figure out Serenity sales. We do this by plugging the MAX and MIN totals for Four Brothers into a simple equation derived from the Serenity sales Index for this week:
MIN Serenity sales = MIN possible FB sales * Serenity sales index
MIN Serenity Sales = 1,503,600.8 * .558 = 839,008.8
MAX Serenity sales = MAX possible FB sales * Serenity sales index
MAX Serenity sales = 2,876,968.5 * .558 = 1,605,348.1
To Summarize 1,605,348 units > Serenity sales the 1st week > 839,008.8 units
So Serenity sold between 839,009 and 1,605,348 units for the week of December 20-25th.
Update:
[quote name='"stfletch"']In the week that Fantastic Four was top, Dukes of Hazzard was 2nd in its first week, and was 75th for the year, selling 53.5% of Fantastic Four.
0.535*3.7mil = 1.98mil fo DoH.
Now Four Brothers was 68th for the year in its first week and so must have sold at least 1.98mil units (probably a bit more). But being conservative and without resorting to speculation, we have for Serenity
0.558*1.98mil = 1.10mil for Serenity minimum
[/quote]
So with the revised MIN, Serenity sold between 1,104,840 and 1,605,348 units for the week of December 20-25th.
I'll update with 2nd week totals as soon as I notice when they update the Hollywood Reporter dvd chart for the week ending Jan. 1.