9. DDT is a pesticide banned in the United States for its danger to humans and animals. In an experiment on the impact of DDT, six rats were exposed to DDT poisoning and six rats were not exposed. For each rat in the Page 2 Name: Class: Date: Statistics-Final Review experiment, a measurement of nerve sensitivity was recorded. The researchers suspected that the mean nerve sensitivity for rats exposed to DDT is greater than that for rats not poisoned. The data follow. Poisoned rats: 12.207 16.869 25.050 22.429 8.456 20.589 Unpoisoned rats: 11.074 9. 686 12. 064 9 351 8. 182 6. 642 Let u be the mean nerve sensitivity for rats poisoned with DDT. Let u be the mean nerve sensitivity for rats not poisoned with DDT. The numerical value of the t statistic is. [x1 17. 6 x_2 9. 49 s1 6. 34 32 1.95] a. 0.57. b. 1.93. c. 6. d. 2.99