2 Sample Z Interval Calculator

Confidence interval for the difference in 2 means σ known.

 

Example

Value	Keystroke	Display	Description
.99	C Level	0.9900	Stores the C Level value.
5	n1	5.000	Stores the n1 value.
131	x̄1	131.0	Stores the x̄1 value.
15.5	σ1	15.50	Stores the  σ1 value.
5	n2	5.000	Stores the n2 value.
117	x̄2	117.0	Stores the x̄2 value.
13.5	σ2	13.50	Stores the  σ2 value.
	Z Int	47.36	Calculates the Z 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	-9.678	The lower limit
	ROLL	37.68	The upper limit

The History Detail

2 Sample Z Interval
          14.00 : The difference in sample means.
          37.68 : The upper limit.
         -9.678 : The lower limit.
         0.9900 : The confidence level.
          5.000 : The sample size 1, n1.
          131.0 : The sample 1 mean, x̄1.
          15.50 : The sample 1 sd of population, σ1.
          5.000 : The sample size 2, n2.
          117.0 : The sample 2 mean, x̄2.
          13.50 : The sample 2 sd of population, σ2.
          47.36 : The Confidence interval for the difference in 2 means σ known.

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

Reference:

Confidence Interval - Wikipedia