Question

Two fuel additives are tested to determine their effect on miles per gallon for passenger cars. Test results for 12 cars follow; each car was tested with both fuel additives Additive Car 19.12 23.56 21.03 18.15 21.23 24.77 15.16 17.55 20.87 24.23 22.21 24.02 2 17.05 20.77 21.57 16.06 21.22 22.8 17.2 13.98 20.03 20.15 22.78 23.7 4 6 8 10 12 Use α-.05 and the Wilcoxon signed-rank test to see whether there is a significant difference between the median miles per gallon for the additives. Use Table 1 of Appendix B a. What are the null and alternative hypotheses? Ho : Median for Additive 1 - Median for Additive 2 equal to o Ha : Median for Additive 1 - Median for Additive 2 not equal to o b. What is the mean and standard deviation of the normal distribution that can be used for this statistical test (to 4 decimals if necessary)? Mean Standard deviation c. What is the value of the test statistic (to 2 decimals) 39 12.7475 1.92 What is the p-value for the hypothesis test (to 4 decimals)? 0.0466 Conclude There is a significant difference in the median miles per gallon for the two additives. V

can someone help me find C. I am not sure why i am getting the wrong answer

Answer 1

sign/Absolute Rank signed rank 23 S6 20 77 9 3 8 21:03 21 ST 16-о,6 21,22 24.11 22.3 11.2 1155 13.93 26.03 20 15 2.2. 7 3 2:09 1.9S 3 61 8. S+ 20.8 t 4.03 I o 20.81 12. 12 34 33 22. 2) 4 24. 02 23.7 0.32 T 13 Test statistic ninti) ninti) Canti 12 Ci2 t1) 1 3 12(12 +1) (24+1 2.H i 3 39 162.5

The resuit statistica ly signiticant There is a significant differenein tns median miles per gallon for the to odolitives