STATISTIK “Hypothesis Testing” Chapter 5 Sulidar Fitri, M.Sc Reference: Muohio
Did the intervention change attitudes? Research Question Does a “college motivational” seminar influence college student’s attitudes about college? A sample (n = 100) of college students is put through the program: Did the intervention change attitudes? Survey of Study Habits & Attitudes (0 – 200; less - more favorable) = 115 = 30 Known population parameters: miu-=mean of populasi Sigma lower case= standar deviasi di populasi = 126
Attitudes do seem improved—the mean value from the sample is larger than the known population average Remember: SAMPLES VARY! Could this apparent improvement just be due to chance? How can we tell?
Hypothesis Testing: In this case, compare to known
Setting up the Hypotheses:
Retain=menahan. menguasai
miu-=mean of populasi Sigma lower case= standar deviasi di populasi
Stringent=ketat
a) Kesalahan tipe I adalah kesalahan yang terjadi apabila Ho ditolak padahal Ho benar. Jenis kesalahan ini dilambangkan dengan α . b) Kesalahan tipe II adalah kesalahan yang terjadi apabila Ho diterima padahal Ho salah. Jenis kesalahan ini dilambangkan dengan β .
QUIZZ
1. PLEASE CALCULATE The Probability of each “X” 9 1 8 3 7 4 6 2
2. Please fill in the blank columns when = 19 , = 5 ?? X X - (X - )/ Z 26 26 – 19 = 7 7 / 5 +1.4 18 20 12 Z= +1.4 -0.2 +0.2 -1.4
3. From the table below, please calculate the S2 (variance) and S(Standard Deviation) !! Student Test Score X (X- ) (X- )2 Eliot 3 3 – 5 = -2 Don 2 2 – 5= -3 Janice 5 5 – 5= 0 Amanda 9 Duane 1 Chris 8 Stephanie Denise 4 S2=E(x-xbar)2/n-1 S=akar S2
4. Given a p-value of 0.065, and using the customary α = 5%, the conclusion should be: Do not reject the null hypothesis Reject the null hypothesis Not enough information to determine Whatever
5. A skeptical paranormal researcher claims that the proportion of Americans that have seen a UFO, p, is less than 5 in every one thousand. HO: p< 0.005 H1: p>0.005 HO: p> 0.005 H1: p< 0.005 HO: p>0.005 H1: p< 0.005 HO: p < 0.005 H1: p > 0.005
Any Queries ?