- Cách dùng bảng Z-score: (Normal Distribution & Population Distribution known)
+ Find the First Two Digits of the Z-Score
If your z-score is, say : 1.96
First part: 1.9
Second part (column header): 0.06
You will go to:
Row labeled 1.9
Column labeled 0.05
+ Use the Table: A z-table shows P(Z < z)
z = 1.96 P(0< Z < 1.96) = 0.4750 → P(0 < Z <x): add 0,5 =
0.5+0.4750=0.9750 (nếu tính ra z âm thì lấy 0,5 trừ đi)
value below the mean: z is negative
value above the mean: z is positive
If you want:
P(Z > z): do 1 − P(Z<z)
P(a < Z < b): subtract P(Z < b) − P(Z < a)
- Cách dùng bảng t-score: (Population Distribution unknown)
+ df = n - 1

Preview text:

-
Cách dùng bảng Z-score: (Normal Distribution & Population Distribution known)
+ Find the First Two Digits of the Z-Score
● If your z-score is, say 1.96: ○ First part: 1.9
○ Second part (column header): 0.06 ● You will go to: ○ Row labeled 1.9 ○ Column labeled 0.05
+ Use the Table: A z-table shows P(Z < z)
● z = 1.96 P(0< Z < 1.96) = 0.4750 ⇒
→ P(0 < Z 0.5+0.4750=0.9750 (nếu tính ra z âm thì lấy 0,5 trừ đi)
○ value below the mean: z is negative
○ value above the mean: z is positive ● If you want:
○ P(Z > z): do 1 − P(Z○ P(a < Z < b): subtract P(Z < b) − P(Z < a)
- Cách dùng bảng t-score: (Population Distribution unknown) + df = n - 1