User Manual
20090601
When the two population standard deviations are equal (pooled) 
When the two population standard deviations are not equal (not pooled) 
Definition of Terms 
C-Level :  confidence level (0 
 C-Level < 1)
List(1) :  list where sample 1 data is located 
List(2) :  list where sample 2 data is located 
Freq(1) :  frequency of sample 1 (1 or list name) 
Freq(2) :  frequency of sample 2 (1 or list name) 
Pooled :  On or Off
M
1
 :  sample mean of sample 1 data
s
x
1
:  sample standard deviation of sample 1 (s
x
1
 0)
n
1
 :  size of sample 1 (positive integer) 
M
2
 :  sample mean of sample 2 data
s
x
2
 :  sample standard deviation of sample 2 (s
x
2
 0)
n
2
 :  size of sample 2 (positive integer) 
Calculation Result Output 
Lower :  interval lower limit (left edge) 
Upper :  interval upper limit (right edge) 
df
 :  degrees of freedom
M
1
 :  sample mean of sample 1 data
M
2
 :  sample mean of sample 2 data
s
x
1
 :  sample standard deviation of sample 1
s
x
2
 :  sample standard deviation of sample 2
s
p
 :  pooled sample standard deviation (Displayed only when pooling is 
turned on.) 
n
1
 :  size of sample 1
n
2
 :  size of sample 2
Lower = (o
1
 – o
2
)– t
2
n
1
+n
2
–2
sp
2
n
1
1
+
n
2
1
Upper = (o
1
 – o
2
)+ t
2
s
p
2
n
1
+n
2
–2
n
1
1
+
n
2
1
Lower = (o
1
 – o
2
)– t
2
n
1
+n
2
–2
sp
2
n
1
1
+
n
2
1
Upper = (o
1
 – o
2
)+ t
2
s
p
2
n
1
+n
2
–2
n
1
1
+
n
2
1
Lower = (o
1
 – o
2
)– t
df
2
+
n
1
s
x
1
2
n
2
s
x
2
2
Upper = (o
1
 – o
2
)+ t
df
2
+
n
1
s
x
1
2
n
2
s
x
2
2
Lower = (o
1
 – o
2
)– t
df
2
+
n
1
s
x
1
2
n
2
s
x
2
2
Upper = (o
1
 – o
2
)+ t
df
2
+
n
1
s
x
1
2
n
2
s
x
2
2
C = 
df = 
1
C
2
n
1
–1
+
(1–C)
2
n
2
–1
+
n
1
n
1
n
2
s
x1
2
s
x1
2
s
x2
2
C = 
df = 
1
C
2
n
1
–1
+
(1–C)
2
n
2
–1
+
n
1
n
1
n
2
s
x1
2
s
x1
2
s
x2
2
7-10-9
Confidence Intervals










