document.write( "Question 1047079: Find the t-value for a 90% confidence interval when the sample size is 20. \n" ); document.write( "
Algebra.Com's Answer #662607 by ewatrrr(24785)\"\" \"About 
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document.write( "Hi  
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document.write( " t-value for a 90% confidence interval when the sample size is 20
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document.write( "t-value where .95 of Distribution Curve is the left of that t-value
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document.write( "Can use Ti:  
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document.write( "t = invT(.95, 19)  Check with a table or statttek.com
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document.write( "	CI 90%	CI 95%	CI 99%	
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document.write( "DF	t-value			
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document.write( "	0.1	0.05	0.01	0.001
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document.write( "1	6.31	12.71	63.66	636.62
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document.write( "2	2.92	4.3	9.93	31.6
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document.write( "3	2.35	3.18	5.84	12.92
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document.write( "4	2.13	2.78	4.6	8.61
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document.write( "5	2.02	2.57	4.03	6.87
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document.write( "6	1.94	2.45	3.71	5.96
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document.write( "7	1.89	2.37	3.5	5.41
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document.write( "8	1.86	2.31	3.36	5.04
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document.write( "9	1.83	2.26	3.25	4.78
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document.write( "10	1.81	2.23	3.17	4.59
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document.write( "11	1.8	2.2	3.11	4.44
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document.write( "12	1.78	2.18	3.06	4.32
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document.write( "13	1.77	2.16	3.01	4.22
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document.write( "14	1.76	2.14	2.98	4.14
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document.write( "15	1.75	2.13	2.95	4.07
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document.write( "16	1.75	2.12	2.92	4.02
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document.write( "17	1.74	2.11	2.9	3.97
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document.write( "18	1.73	2.1	2.88	3.92
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document.write( "19	\"highlight%281.73%29\"	2.09	2.86	3.88
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document.write( "20	1.72	2.09	2.85	3.85\r
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document.write( "Note: z-value
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document.write( " = CI	z = value
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document.write( "90%	z =1.645
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document.write( "92%	z = 1.751
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document.write( "95%	z = 1.96
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document.write( "98%	z = 2.326
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document.write( "99%	z = 2.576\r
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