Spinning penny page (as of April 4, 2004)

Spinning penny*: Proportion of heads p =  (??)   Sample data:  Students spun pennies 50 times each.
                                                       Fall 1999 pooled   13 students      p-hat =  321/650 = .4938
                                                      Spring 2001 pooled  15 students      p-hat = 398/750 = .531
                                                           Fall 2001 Math 251   7 students p-hat = 174/350 = .497
                                                          Fall 2001 Math 151   9 students   p-hat = 229/450 =  .509
                                              Pooled all       43 previous      students   p-hat =1122/2150 = .522
Flicked:    Spring 2002 7 students p-hat = 157/350 =  .449
                       Without the "10H" outlier: p-hat = 147/300 =  .49
                   Fall 2002  6 students p-hat = 151/300 =  .503
                   Spring 2003 7 students p-hat = 151/350 = .431
                    Spring 2004 1 student  24/50 = .48
                  Pooled 21 students  p-hat = 483/1050 = .46             
Twirled: Spring 2002 13 students p-hat = 296/650 =  .455
                   Fall 2002  8 students p-hat = 183/400 =  .458
                  Spring 2003 13 students p-hat = 308/650 = .474
                  Spring 2004 8 students p-hat = 209/400 = 0.523                
                  Pooled 42 students  p-hat =  996/2100  =.474  
Both:  Spring 2004 4 students p-hat = 101/200 =.505

  Combined flicked & twirled & both  last 4 terms 54 students, p-hat =  1580/3350 =  1246/2700= .472

Sampling variability: Distribution of all individual students' p-hats, Proportion of heads/50
 flicks marked with x, Fall 02+  Spring 03, Spring 04

o
-+-
.20 		-+- .22 -+-
.24 		-+-
.26 		x
-+-
.28
-+-
.30 		o
o
o
-+-
.32

x
-+-
.34

 o
-+-
.36 		o
x
o
o
-+-
.38		 o
e
o
o
-+-
.40 		e
o
o
o
o
x
o
o
-+-
.42		 o
o
o
o
o
o
o
o
-+-
.44		 o
o
x
o
o
o
o
o
o
o
o
-+-
.46		 o
x
x
x
o
o
o
-+-
.48

o
x
o
o
o
o
o
o
o
o
o
o
o
-+-
.50

 x
o
o
o
o
o
o
o
o
o
o
o
o
o
o
-+-
.52		 e
e
o
x
o
x
o
o
o
o
o
o
o
o
o
o
-+-
.54		 o
o
o
o
o
-+-
.56 		o
o
o
o
-+-
.58 		o
-+-
.60 		o
o
-+-
.62 		o
-+-
.64
-+-
.66		 o
.74e
-+-
.68+

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Flicked:
Fall 02, Spring 03, 7 students, Spring 04, 1 student


-+-
.20 		-+- .22 -+-
.24 		-+-
.26 		x
-+-
.28
-+-
.30 		-+-
.32

x
-+-
.34
-+-
.36 		x
x
-+-
.38
-+-
.40 		x
-+-
.42		 x
-+-
.44		 x
-+-
.4		 x
x
x
-+-
.48		 x
-+-
.50		 x
-+-
.52		 x
x
-+-
.54
-+-
.56
-+-
.58
-+-
.60
-+-
.62
-+-
.64
-+-
.66
-+-
.68

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Twirled:
Fall 02, Spring 03, 13 students, Spring 04, 8 students


-+-
.20 		-+- .22 -+-
.24 		-+-
.26
 -+-
.28
-+-
.30 		-+-
.32


-+-
.34

 o
-+-
.36 		o
-+-
.38		 o
o
-+-
.40 		o
o
o
o
-+-
.42		 o
o
o
o
o
-+-
.44		 o
o
o
o
o
-+-
.46		 o
-+-
.48		 o
-+-
.50
-+-
.52		 o
o
o
-+-
.54		 o
o
o
-+-
.56 		o
-+-
.58 		o
-+-
.60 		o
-+-
.62
-+-
.64
-+-
.66		 o
-+-
.68

Both: Spring 04, 5 students

-+-
.20 		-+- .22 -+-
.24 		-+-
.26
 -+-
.28
-+-
.30 		-+-
.32


-+-
.34
-+-
.36
-+-
.38		 e
-+-
.40 		e
-+-
.42
-+-
.44
-+-
.46
-+-
.48
-+-
.50
-+-
.52		 e
e
-+-
.54
-+-
.56
-+-
.58
-+-
.60
-+-
.62
-+-
.64
-+-
.66		 .74
-+-
.68+

Sievers home  Spinningpenny04.htm 
4/4/04
This page belongs to Sally Sievers who is solely responsible for its content. Please see our statement of responsibility.
*Text answer book says spinning pennies often approach 40% heads in the long term.  Not here, yet. Are Wells Women different?!



-+-
.20 		-+- .22 -+-
.24 		-+-
.26
 -+-
.28
-+-
.30 		-+-
.32


-+-
.34
-+-
.36
-+-
.38
-+-
.40
-+-
.42
-+-
.44
-+-
.46
-+-
.48
-+-
.50
-+-
.52
-+-
.54
-+-
.56
-+-
.58
-+-
.60
-+-
.62
-+-
.64
-+-
.66
-+-
.68
xxxxxx xxxxx