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--- c:ps1-1:ci_note [2023/11/20 08:52] – created hkimscil
+++ c:ps1-1:ci_note [2024/11/20 08:18] (current) – hkimscil
@@ Line 5: / Line 5: @@
 p1 <- rnorm2 (100000000, mean=70, sd=10)
-a1 <- qnorm(.95)
-a2 <- qnorm(.975)
-a3 <- qnorm(.995)
+set.seed(101)
 s.size <- 16
 s1 <- sample(p1, s.size, replace=T)
-m.s16 <- mean(s1)
+s1
-sd.s16 <- sd(s1)
+m.s1 <- mean(s1)
+sd.s1 <- sd(s1)
+m.s1
+sd.s1
 se <- sd.s1/sqrt(s.size)
-se2 <- se*2
+se2 <- 2*se
-se3 <- se*3
+se3 <- 2*se
-m.s16 - se2
-m.s16 + se2
+m.s1 - se2
+m.s1 + se2
 # or
-se2 <- se*a2
+c2 <- qnorm(.975)
-se3 <- se*a3
+c3 <- qnorm(.995)
-m.s16 - se2
+c2
-m.s16 + se2
+c3
+se2 <- c2*se
+se3 <- c3*se
+m.s1 - se2
+m.s1 + se2
+</code>
+<code>
+> rnorm2 <- function(n,mean,sd) {
+>    mean + sd * scale(rnorm(n))
+>    }
+>
+> p1 <- rnorm2 (100000000, mean=70, sd=10)
+>
+> set.seed(101)
+> s.size <- 16
+> s1 <- sample(p1, s.size, replace=T)
+> s1
+ [1] 64.87746 78.68130 50.61449 62.18639 68.08899 63.07744 54.48954 69.26928 55.92358
+[10] 70.06123 60.38630 87.91813 78.55023 69.78835 63.15719 64.35994
+> m.s1 <- mean(s1)
+> sd.s1 <- sd(s1)
+> m.s1
+[1] 66.33936
+> sd.s1
+[1] 9.59219
+>
+> se <- sd.s1/sqrt(s.size)
+> se2 <- 2*se
+> se3 <- 2*se
+>
+>
+> m.s1 - se2
+[1] 61.54327
+> m.s1 + se2
+[1] 71.13546
+>
+> # or
+> c2 <- qnorm(.975)
+> c3 <- qnorm(.995)
+> c2
+[1] 1.959964
+> c3
+[1] 2.575829
+>
+> se2 <- c2*se
+> se3 <- c3*se
+>
+> m.s1 - se2
+[1] 61.63928
+> m.s1 + se2
+[1] 71.03945
+>
 </code>