2 Sample T Interval Pooled Calculator

Calculates the confidence interval for difference in 2 normal distributions, σ equal and unknown. Pooled.

 

Example

Value	Keystroke	Display	Description
.95	C Level	0.9500	Stores the C Level value.
65	n1	65.000	Stores the n1 value.
1.6	x̄1	1.600	Stores the x̄1 value.
6.7	s1	6.700	Stores the s1 value.
6	n2	6.000	Stores the n2 value.
9.5	x̄2	7.500	Stores the x̄2 value.
1.95	s2	19.50	Stores the  s2 value.
	T Int	12.69	Calculates the T Interval

This calculator also calculates the upper and lower limits and enters them in the stack.
By returning these values to the stack you can use them for other calculations without having to write them down and re-enter them.

Value	Keystroke	Display	Description
	ROLL	-14.25	The lower limit
	ROLL	-1.553	The upper limit

The History Detail

2 Sample T Interval Pooled
         -7.900 : The difference in sample means.
         -1.553 : The upper limit.
         -14.25 : The lower limit.
         0.9500 : The confidence level.
          6.000 : The sample size 1, n1.
          1.600 : The sample 1 mean, x̄1.
          6.700 : The sample 1 sd, s1.
          6.000 : The sample size 2, n2.
          9.500 : The sample 2 mean, x̄2.
          1.950 : The sample 2 sd, s2.
          12.69 : The Confidence interval for the difference in 2 means σ equal, unknown, pooled.

Note that you can enter a "T Int" value and solve for the C Level.

Reference:

Confidence Interval - Wikipedia