A pharmaceutical company has developed a newdrug that they believe could improvestudents'performance on a statistics exam.To test the drug's effects,they randomly select30students,give half of them a control substance(group1),and give the other half the drug(group2).Both groups take the statistics exam,and the graph below portrays the resulting group mean scores.Remember they are expecting an improvement in the experimental group.The drug company sets their significance level(alpha)to.05for the hypothesis test between the two groups(group1=no drug/Control;and group2=drug/Experimental).

Assume your calculated t (obtained) statistic was -1.98. If you were conducting a hypothesis test on this scenario, Step 4 and 5 would look like:

a. Since tobt = -1.98 < tcrit = 1.701 then we would fail to reject the Null and conclude that the drug does not significantly increase students' test scores.

b. Since tobt = -1.98 > tcrit = -2.048 then we would fail to reject the Null and conclude that the drug does not significantly increase students' test scores.

c. Since |tobt = 1.98| < |tcrit = 2.048| then we would fail to reject the Null and conclude that the drug does not significantly increase students' test scores.

d. Since tobt = -1.98 < tcrit = -1.701 then we would reject the Null and conclude that the drug does significantly increase students' test scores.