2. Matrimonial Unrest Mr. & Mrs. Hartford Newly married Having numerous fights Unsure as to the cause(s) Visits a team of a psychologist and a marriage counselor Collect data of various events that may trigger fights
3. Matrimonial Unrest Potential factors for a fight: Number of calories consumed Number of hours of sleep the night before Bad day at work School the next day Number of cups of coffee consumed that day Uncomfortable symptoms of PMS that day Bills paid that day
4. Matrimonial Unrest Hypothesis Testing Define the hypothesis Null hypothesis States the obvious Alternative hypothesis Bears the burden of proof Calculate the test statistic Make a decision If the sample mean is close to the assumed population mean, do not reject the null hypothesis If the sample mean is far from the assumed population mean, reject the null hypothesis
5. One Sample Hypothesis Testingn > 30 m : =AVERAGE() s : =STDEV() zOBS : =STANDARDIZE(x,m, s/SQRT(n)) zCRIT : =NORMSINV(1-a/# of tails) p-value : =(# of tails) * (1-NORMSDIST(ABS(zOBS)))
6. One Sample Hypothesis Testingn < 30 m : =AVERAGE() s : =STDEV() tOBS: =STANDARDIZE(x,m, s/SQRT(n)) tCRIT: =TINV(2a/# of tails,df) p-value : TDIST(ABS(tOBS)),df, # of tails)
7. Not Enough Sleep Null: m <= .267 – Not enough sleep (less than 7 hours) does not lead to more fights. Alternative: m > .267 – Not enough sleep (less than 7 hours) does lead to more fights.
8. Not Enough Sleep Hypothesized Value = .267 Sample Mean = .262 Standard Deviation = .445 Sample Size = 42 Do not Reject the Null zOBS = (.073) zCRIT = 1.645 P-value = .471 a-level = .05
9. Not Enough Sleep Null: m <= .267 – Not enough sleep (less than 6 hours) does not lead to more fights. Alternative: m > .267 – Not enough sleep (less than 6 hours) does lead to more fights.
10. Not Enough Sleep Hypothesized Value = .267 Sample Mean = .250 Standard Deviation = .447 Sample Size = 16 Do not Reject the Null tOBS = (.152) tCRIT = 1.753 P-value = .441 a-level = .05
11. Bills Paid That Day Null: m <= .267 – Bills paid that day does not lead to more fights. Alternative: m > .267 – Bills paid that day does lead to more fights.
12. Bills Paid That Day Hypothesized Value = .267 Sample Mean = .333 Standard Deviation = .516 Sample Size = 6 Do not Reject the Null tOBS = .313 tCRIT = 2.015 P-value = .383 a-level = .05
13. PMS Symptoms That Day Null: m <= .267 – PMS Symptoms that day does not lead to more fights. Alternative: m > .267 – PMS Symptoms that day does lead to more fights.
14. PMS Symptoms That Day Hypothesized Value = .267 Sample Mean = .600 Standard Deviation = .516 Sample Size = 10 Reject the Null tOBS = 2.041 tCRIT = 1.833 P-value = .036 a-level = .05
15. A Bad Day at Work Null: m <= .267 – A bad day at work does not lead to more fights. Alternative: m > .267 –A bad day at work does lead to more fights.
16. A Bad Day at Work Hypothesized Value = .267 Sample Mean = .500 Standard Deviation = .519 Sample Size = 14 Do not Reject the Null tOBS = 1.680 tCRIT = 1.771 P-value = .059 a-level = .05
17. Too Much Coffee Null: m <= .267 – Too much coffee (2+) does not lead to more fights. Alternative: m > .267 – Too much coffee (2+) does lead to more fights.
18. Too Much Coffee Hypothesized Value = .267 Sample Mean = .364 Standard Deviation = .492 Sample Size = 22 Do not Reject the Null tOBS = .925 tCRIT = 1.721 P-value = .183 a-level = .05
19. School the Next Day Null: m <= .267 – School the next day does not lead to more fights. Alternative: m > .267 – School the next day does lead to more fights.
20. School the Next Day Hypothesized Value = .267 Sample Mean = .300 Standard Deviation = .470 Sample Size = 20 Do not Reject the Null tOBS = .314 tCRIT = 1.729 P-value = .378 a-level = .05
