I'm confused with observatory and experiment. This question as whether it's observatory and experimental. if experiment what is the variable and confounding variable. My answers are in black. I'm not sure if it's correct. Thank you

Experiment.Independent variable: records. Confounding: behavior.

(a)To determine whether there is a relationship between the sexual codes of primitive tribes and their behavior toward neighboring tribes, an anthropologist consults available records, classifying each tribe on the basis of its sexual codes (permissive or repressive) and its behavior toward neighboring tribes (friendly or hostile).

Experiment. Independent variable: number of months of formal education. Confounding variable: comprehension scores.

(a)A school psychologist wishes to determine whether reading comprehension scores are related to the number of months of formal education, as reported on school transcripts, for a group of 12-year-old migrant children.

Observatory

(a)To determine whether Graduate Record Exam (GRE) scores can be increased by cramming, an investigator allows college students to choose to participate in either a GRE test-taking workshop or a control (non-test-taking) workshop and then compares the GRE scores earned subsequently by the two groups of students.

Experiment. Independent variable: eating marshmallow. Confounding variable: score

(a)Investigators found that four year-old children who delayed eating one marshmallow in order to eat two marshmallows later, scored higher than non-delayers on the Scholastic Aptitude Test (SAT) taken over a decade later.