Tiffany N. KeysŐ Essay 1:

Friday
the Thirteenth

For
Investigation A, I prepared a spreadsheet in
Microsoft Excel in order to show that for any year there must be at least one
month and at most three months for which the 13^{th} of the month falls
on Friday. I showed this given any
day that January 1^{st} could possibly fall on. The month in which the
13^{th} falls on a Friday has been highlighted.

Click
here to view the spreadsheet for Investigation A

In
order to make comparisons between leap years and non-leap years in Investigation B, I prepared two spreadsheets in
Excel in order to show which months have Friday the 13^{th} in
them. Like Investigation A, I
showed this for any given day in which January 1^{st} could fall on in
non-leap years and leap years.

1.
I
researched that January 1^{st} occurred on a Thursday therefore
resulting in a Friday the 13^{th} in both February and March. From the spreadsheet I prepared, I can
confirm that Thursday is the only day in which January 1^{st} could
fall in a non-leap and leap year in which results in two consecutive Friday the
13^{th} in February and March.

2.
The
next year in which there will be two consecutive Friday the 13^{th} in
February and March will be in 2009.
Since January 1, 2009 will occur on Thursday, my spreadsheet confirms
this.

3.
I
do not think that there is a pattern or cycle for which I can determine which
years between 2000 and 2100 there will be two consecutive Friday the 13^{th}
in February and March because the day in which the first day of the year occurs
appears to be the determining factor for this event. There probably is a pattern or cycle for which one can
determine what day January 1^{st} will fall on.

Click
here to view the spreadsheet for Investigation B