The study ran for several weeks during the semester. About a week after it started, the university announced that they would be holding training sessions for faculty and staff about how to handle situations involving a gunman on campus. This shut down the study for several days as the university needed the lab building for training. The study then resumed according to script after the training. The researchers found that those in the experimental group did not differ in their memories regarding the presence of a gun compared to those in the control condition. That is, the mean score that a gun was present was similar for the experimental group (M = 65%, SD = 11.4%) and the control group (M = 63%, SD = 13.26%). a. Maturation b. Regression to the mean c. Selection d. Mortality e. Instrumentation f. Testing g. History h. Interactions i. Diffusion j. No Threa

option (g)

Step-by-step explanation:

So the question says :

The study ran for several weeks during the semester. About a week after it started, the university announced that they would be holding training sessions for faculty and staff about how to handle situations involving a gunman on campus. This shut down the study for several days as the university needed the lab building for training. The study then resumed according to script after the training. The researchers found that those in the experimental group did not differ in their memories regarding the presence of a gun compared to those in the control condition. That is, the mean score that a gun was present was similar for the experimental group (M = 65%, SD = 11.4%) and the control group (M = 63%, SD = 13.26%). a. Maturation b. Regression to the mean c. Selection d. Mortality e. Instrumentation f. Testing g. History h. Interactions i. Diffusion j. No Threat

ANS ⇒  The correct answer to this question is option G.

We can confirm here that History is the biggest threat to internal validity in the study as a significant period of time was allowed to pass between the testing conditions.

cheers i hope this helped !!!

1.3

step-by-step explanation:

3x2=6   9x+6

bring down the 6 on both sides

6+6=12

12= 9x

divide by 9

12/9 =

1.3 =x