A researcher is investigating whether a reading intervention program improves reading comprehension for second graders. He collects a random sample of second graders and randomly assigns each second grader to participate in the reading intervention program or not participate in the program. The researcher knows that the standard deviation of the reading comprehension scores among all second graders is ? = 13.35.Group 1 consists of n? = 38 second graders who did not participate in the program. Their mean reading comprehension score is M? = 22.8. Group 2 consists of n? = 42 second graders who did participate in the program. Their mean reading comprehension score is M? = 46.1.Of the plots that follow, which best represents a plot of these results?a. Plot Ab. Plot Bc. Plot Cd. Plot DFill in the blanks:The brackets or error bars shown at the top of each bar extend ___ above and below each of the group means. For group 1, the error bar extends ___ units above and below the mean for group 1.1. a. one standard deviationb. one standard error2.a. 13.35b. 2.17c. 15.7d. 2.06

Plot A Plot B 40 35 50 30 10 25 Mean Score 30 Mean Score 20 15 20 10 5 group 2 group 1 group 2 group 1 Group Group Plot C Plot D 50 60 45 50 40- 35 40 30 25 Mean Score ^ 30 Mean Score 20 20 15- 10 10 group 1 group 2 proup 1 group 2 Group Group