Dr. Kusman Sadik, M.Si

Sekolah Pascasarjana Departemen Statistika IPB

Semester Ganjil 2019/2020

Analisis Statistika (STK511)

IPB University─ Bogor Indonesia ─ Inspiring Innovation with Integrity

Sebaran Normal dan

Sebaran Penarikan Contoh (Sampling Distibution)

We have limited our discussion to probability

distributions of discrete random variables. A discrete

random variable takes on only some isolated values,

usually integers representing a count.

We now turn our attention to the probability

distribution of a continuous random variable, one that

can ideally assume any value in an interval.

Variables measured on an underlying continuous

scale, such as weight, strength, life length, and

temperature, have this feature.

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Sebaran peluang p.a. kontinu X disebut sebagai fungsi

kepekatan peluang X (probability density function),

biasanya ditulis f(X)

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Untuk peubah acak X kontinu, maka:

P(X = k) = 0

P(X ≤ k) = P(X < k)

P(X ≥ k) = P(X > k)

dimana k adalah konstanta

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A continuous random variable X also has a mean,

or expected value E(X), as well as a variance

V(X) and a standard deviation.

Their interpretations are the same as in the case

of discrete random variables, but their formal

definitions involve integral calculus and are

therefore not pursued here.

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Mean = Median Symmetric

Mean < Median Skewed to left Mean > Median Skewed to right

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Sebaran Normal merupakan salah satu sebaran

untuk peubah acak kontinu.

Apabila peubak acak X menyebar Normal dengan

E(X) = μ dan V(X) = σ2 ditulis sebagai berikut:

X ~ Normal (μ, σ)

μ dan σ disebut sebagai parameter sebaran Normal

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Johnson : Example 7 (hlm. 240)

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Selesaikan contoh soal di atas menggunakan Minitab,

kemudian bandingkan hasilnya.

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Johnson (Exercise 7.21), hlm. 284

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Johnson (Exercise 7.21), hlm. 284

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Selesaikan soal ini menggunakan Minitab, kemudian

bandingkan hasilnya dengan jawaban Anda pada No.1 di

atas.

Johnson (Exercise 7.41), hlm. 291

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Johnson (Exercise 7.46), hlm. 292

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Johnson (Exercise 7.48), hlm. 292

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Johnson (Exercise 7.48), hlm. 292

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Selesaikan soal ini menggunakan Minitab, kemudian

bandingkan hasilnya dengan jawaban Anda pada No.5 di

atas.

Johnson, R.A. and Bhattacharyya, G.K. 2010.

Statistics, Principles and Methods 6th. John Wiley

& Sons, Inc., New York.

Montgomery, D.C. 2013. Design and Analysis of

Experiments 8th. John Wiley & Sons, Inc.,

Canada.

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