MODUL 9 INFERERENTIAL ANALYSIS AND INTERPRETATION OF ANALYSIS RESULT (HYPOTHESIS TEST)

Case 1.

Theoretical Distributions, Confidence Interval, Area under Normal DistributionFor statistical tests, it is important to understand probability theory, theoretical distributions, confidence intervals (CI), one-tail and two-tail statistical tests, and error in interpreting hypothesis tests.

Learning Task 1Discuss the following1. Explain the definition of probability, marginal probability, conditional probability and joint probability Probability: kemungkinanterjadinyasuatukejadian. Marginal probability: peluangsatukejadianakanterjadi. Contoh: Conditional probability: peluangsatukejadianakanterjadikarenasuatukondisi Contoh Joint probability: peluangkejadian A dan B terjadibersamaan Contoh

2. Explain the definition of the addition rule and multiplication rule Addition rule :probabilitasmunculnya A atau B samadenganjumlahprobabilitaskeduanya Multiplication rule :probabilitasmunculnya A dan B samadenganhasil kali probabilitaskeduanya

3. Table 1. Cross tabulation between economic status and nutritional status of children under 5 years in DesaAmerta 2012Economic statusUnder nourishNormalObeseTotal

poor3035570

affluent10551580

Total409020150

Based on table above, calculate the probability:a. What is the probability if we selected one child randomly from DesaAmerta, will be an under nourish kids in? What type of probability it is? 40/150=4/15 Marginal probability

b. What is the probability of under-nourish, if the kids from poor family? What type of probability it is? 30/70=3/7 Conditional probability

c. Probability of a child who is randomly selected from this group will be from poor family or an obese kid? 70/150 + 20/150 = 90/150 = 3/5 Marginal probability,with addition rule

d. Probability of a child who is randomly selected from this group will be from affluent family and is obese 15/150 = 1/10 Joint probability

4. Describe the type of probability distribution of a random variable. Give examples! Distribusi probabilitas untuk data kontinu : normal distribution distribusi T distribusi F chi-square distribution Distribusi probabilitas untuk data discrete : Binomial Poison

5. Describe the characteristic of normal distribution and the use of normal distribution? Kurva berbentuk lonceng simetris (symetrical bell shape) Mean = median = modus Disusun dari variabel random tertentu Mean + 1 SD = 68% Mean + 1,96 SD = 95% Mean + 2,57 SD = 99% Luas kurva total = 1 = 100% Digunakan untuk menentukan jenis uji hipotesis serta menghitung nilai Confidence Interval (CI)

6. Distinguish the difference between normal distribution/Gaussian distribution and standard normal distribution Kurva berbentuk lonceng simetris (symetrical bell shape) Mean = median = modus Disusun dari variabel random tertentu Mean + 1 SD = 68%Mean + 1,96 SD = 95%Mean + 2,57 SD = 99% Luas kurva total = 1 = 100% Digunakan untuk menentukan jenis uji hipotesis serta menghitung nilai Confidence Interval (CI)

7. Describe about z score and its use? Z score is a deviation of a value from mean is SD (standard deviation) scale. How many SD apart from the mean. Untukmemperkirakanprobabilitas

8. If from a study we found the mean of Hb level from 200 samples of children is 11.8 mg/dl, and the standard deviation is 0.5mg/dl. It is assumed that data was normally distributed. Based on the used of normal distribution and the area under normal curve (z score)a. What is the probability of children in the population has Hb level > 12mg/dl

b. What is the probability of children in the population has Hb level