Unformatted text preview: t Stat0.05 P(T<=t) onetail 0.48 Ignore these values  for a onetail test t Critical onetail 1.81 Ignore these values  for a onetail test P(T<=t) twotail 0.96 t Critical twotail 2.23 Verify: 2.23 Two Samples  Using Excel's ttest for Two Independent Samples  Case with different values of n x A x B Sample numbers of data points ( n ): Sample means ( x _bar): Sample standard deviations ( S ): Sample variances ( S 2 ): OR, mathematically, μ A = B Calculate the tstatistic and the pvalue: tstatistic: [ t = ( x _bar A x _bar B ) / SQRT( S A 2 / n A + S B 2 / n B ) df real = [ df = ROUND(df real ,0) ] pvalue: [ p = TDIST(ABS( t ),df,2) ] (ToolsData AnalysistTest: TwoSample Assuming Unequal Variances ) This is our tstatistic This is our pvalue This is the critical value of t ( t α /2 ) for = 0.05 (95% confidence) t /2 = [ t /2 = TINV(0.05,df) ]...
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This note was uploaded on 07/23/2008 for the course ME 345 taught by Professor Staff during the Spring '08 term at Penn State.
 Spring '08
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