In: Statistics and Probability
5. A professor theorizes that science students perform differently on multiple choice tests than on essay tests. The professor recruited 6 science students and had them take both types of test. Their test scores were recorded. The data are given in the following table. Based on the data, can you support the professor’s theory? Perform an appropriate test at α = 0.01.
Student |
1 |
2 |
3 |
4 |
5 |
6 |
Multiple choice |
8 |
7 |
9 |
4 |
6 |
5 |
Essay |
5 |
8 |
7 |
3 |
9 |
4 |
one-sample Z-test one-sample t-test independent-samples t-test paired-samples t-test
here we use independent-samples t-test with
(step1)
null hypothesis H0:1=2 (science students perform same (or not different) on multiple choice tests(1) than on essay tests (2))and
alternate hypothesis H1:1≠2 (science students perform differently on multiple choice tests(1) than on essay tests (2))
(step 2) critical t(0.01/2,10)=3.17
statistic t=|(mean1-mean2)|/((sp*(1/n1 +1/n2)1/2)=0.4060 with df is n=n1+n2-2 =10
and sp2=((n1-1)s12+(n2-1)s22)/n=4.55
(step 3) Accept null hypothesis H0
(step4) since two tailed p-value is more than alpha=0.01, so we accept H0 and conclude that science students perform same (or not different) on multiple choice tests(sample1) than on essay tests (sample2))and
sample | mean | s | s2 | n | (n-1)s2 | |
multiple choice | 6.5000 | 1.8708 | 3.5000 | 6 | 17.5000 | |
essay | 6.0000 | 2.3664 | 5.6000 | 6 | 28.0000 | |
difference= | 0.5000 | sum= | 9.1000 | 12 | 45.5000 | |
sp2= | 4.5500 | |||||
sp= | 2.1331 | |||||
SE= | 1.2315 | |||||
t= | 0.4060 | |||||
one tailed | p-value= | 0.3466 | ||||
two tailed | p-value= | 0.6933 | ||||
two tialed critical | t(0.05) | 2.2281 | ||||
one tailed critical | t(0.05) | 1.8125 |