Type the three critical-value calls and their output — the z-table’s 1.645, the hand Welch row 9, and R’s Satterthwaite df.
Type the three critical-value calls and their output — the z-table’s 1.645, the hand Welch row 9, and R’s Satterthwaite df.
Answer
> qnorm(0.95); qt(0.95, 9); qt(0.95, 19.62) [1] 1.644854 [1] 1.833113 [1] 1.72634
1.644854 rounds to the sheet’s 1.645; 1.833113 to row 9’s 1.833; 1.72634 is the critical value at R’s fractional df — smaller because the df is larger.
H-W3, H-W7, H-W9 (every example checked against R, REFERENCE for shape); R output from a live Rscript session; original