ผลต่างระหว่างรุ่นของ "Week11 practice 2"

รุ่นแก้ไขเมื่อ 01:29, 6 พฤศจิกายน 2557

Suppose that you take $n$ samples $X_{1},X_{2},\ldots ,X_{n}$ independently from the same distribution.

The statistic

${\bar {X}}={\frac {X_{1}+X_{2}+\cdots +X_{n}}{n}}={\frac {1}{n}}\sum _{i=1}^{n}X_{i}$

is called a sample mean.

@@ แถว 4: / แถว 4: @@
 === Sample means ===
-The statistic <math>\bar{X} = \frac{1}{n}\sum_{i=1}^n X_i</math> is called a '''sample mean.'''
+The statistic
+<center>
+<math>\bar{X} = \frac{X_1+X_2+\cdots+X_n}{n} = \frac{1}{n}\sum_{i=1}^n X_i</math>
+</center>
+is called a '''sample mean.'''
 === Sample variances and sample standard deviations ===