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--- sample_proportions_is_not_a_binomial_distribution:code01 [2025/11/12 07:40] – removed - external edit (Unknown date) 127.0.0.1
+++ sample_proportions_is_not_a_binomial_distribution:code01 [2025/11/12 07:40] (current) – ↷ Page moved from sampling_proportion_is_not_binomial_distribution:code01 to sample_proportions_is_not_a_binomial_distribution:code01 hkimscil
@@ Line 1: / Line 1: @@
+<code>
+- pbinom(30, 100, 1/4)
+pbinom(30, 100, 1/4, lower.tail = F)
+# 위의 문제를 normal distriubtion으로 계산한다면
+# exp(k) = np, var(k) = npq 이므로
+n <- 100
+p <- 1/4
+q <- 1-p
+e.k <- n*p
+v.k <- n*p*q
+e.k
+v.k
+sd.k <- sqrt(v.k)
+x <- 0:50
+plot(dbinom(x, n, p), type="l")
+# 위에서 P(x > 30) 을 묻는 문제
+pnorm(30, e.k, sd.k, lower.tail = F)
+# cc를 적용하면
+pnorm(30.5, e.k, sd.k, lower.tail = F)
+# P(x<_25)?
+pbinom(25, n, p)
+pnorm(25, e.k, sd.k)
+pnorm(25.5, e.k, sd.k)
+</code>