Casio FX 1.0 PLUS, FX 2.0, FX 2.0 PLUS u2-Sample t Interval

	1-3-9
	Confidence Interval (INTR)
o ..................................	mean of sample
xσn-1 .............................	sample standard deviation (xσn-1>0)
n ..................................	size of sample (positive integer)

After setting all the parameters, align the cursor with [Execute] and then press the function key shown below to perform the calculation.

• 1(CALC) ... Performs the calculation.

Calculation Result Output Example

Left ..............................	interval lower limit (left edge)
Right ............................	interval upper limit (right edge)
o ..................................	mean of sample
xσn-1 .............................	sample standard deviation
n ..................................	size of sample

u2-Sample t Interval

2-Samplet Interval calculates the confidence interval for the difference between two population means when both population standard deviations are unknown. The t interval is applied to t distribution.

The following confidence interval applies when pooling is in effect. The value 100 (1 – α) % is the confidence level.

		α		1					1
Left = (o1 – o2)– tn1+n2 –2				xp σn–12				+
		2			n	1				n	2
Right = (o1 – o2)+ tn1+n2 –2			α	xp σn–12			1		+		1
			2			n1					n2
xpσn–1 =	(n1–1)x1σn–12+(n2–1)x2σn–12
	n1 + n2	– 2

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