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TEACHING TESTING, P-VALUES, AND CIs WITH THE BINOMIAL AND MINITAB AND W/OUT THE NORMAL DISTRIBUTION. DSI BALTIMORE NOVEMBER 18 2013. JOSEPH G VAN MATRE SCHOOL OF BUSINESS UAB. PROBLEM SETTING. ONE-SEMESTER REQUIRED STAT COURSE FOR MBAs
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TEACHING TESTING, P-VALUES, AND CIs WITH THE BINOMIAL AND MINITAB AND W/OUT THE NORMAL DISTRIBUTION DSI BALTIMORE NOVEMBER 18 2013 JOSEPH G VAN MATRE SCHOOL OF BUSINESS UAB
PROBLEM SETTING • ONE-SEMESTER REQUIRED STAT COURSE FOR MBAs • TRADITIONAL COURSE WITH PROBABLITY DISTRIBUTIONS AND SAMPLING DISTRIBUTIONS BEFORE INFERENCE • LITTLE TIME LEFT FOR REGRESSION ANALYSIS AT END OF COURSE • MINITAB IS THE STAT PACKAGE • CONCERN THAT WILL BE FACED WITH SAME PROBLEM IN UNDERGRADUATE COURSE (CURRENTLY TWO REQUIRED COURSE)
SOLUTION • INTRODUCE PROBABILITY DISTRIBUTIONS WITH EXPECTED VALUE AND VARIANCE (NO CHANGE) • INTRODUCE ONLY ONE “NAMED” PROBABILITY DISTRIBUTION, THE BINOMIAL: FUNCTION, PARAMETERS, W/ CALCULATOR AND MINITAB PROBLEMS • NO SAMPLING DISTRIBUTIONS • INTRODUCE INFERENCE: HYPOTHESIS TESTS, P-VALUES AND CIs • INTRODUCE THE PROPORTIONS TEST AND THE MEDIAN TEST: OBTAIN ANSWERS W/ BINO ONLY AND THEN W/ MTB BUILT-IN TESTS
CS RESEARCH 2/16/12 7/1/12:BMY-31 E(X)=22.2
BIOTECH INVESTMENT: FIRM HAS TESTED DRUG ON FOUR PTS. AND CURED ALL; CURRENT STANDARD OF CARE CURES 50% IS DRUG CURE RATE NO BETTER THAN STD CARE? Ho: P<=.50 Ha: P>.50 P-VALUE=P(SAMPLE RESULT AS OR MORE EXTREME THAN THAT OBSERVED, GIVEN Ho TRUE= P(X<=0|n=4, P=.5)=.0625 W/ CALCULATOR LEARN TO WRITE P-VAL AS A CUMULATIVE DOWNWARD PROB B/C OF MINITAB Cumulative Distribution Function Binomial with n = 4 and p = 0.5 x P( X <= x ) 0 0.0625
CONFIDENCE INTERVAL: A (1-ALPHA) CI CONSISTS OF ALL HYPOTHETICAL VALUES THAT WOULD NOT BE REJECTED IN A TEST AT THE ALPHA LEVEL OF SIGNIFICANCE
SWITCHED BACK TO NUMBER CURED; NOTE CI IS INCLUDED BY MTB
RELATED PROBLEMS: CURRENT STANDARD OF CARE=.30 n=4, ALL 4 CURED Ho: P<=.30 P-VAL=.0081 MORALE: SMALL SAMPLES CAN PROVIDE SIGNIFICANT RESULTS CURRENT STANDARD OF CARE=.50 n=10, 9 ARE CURED Ho: P<=.50 P-VAL=.0107 MORALE: CAN HAVE SOME FAILURES IF n IS LARGER