how do I determine which hypothesis test to use?

Part I: Determine the best hypothesis test to recommend for each scenario presented below. Use the following tests as recommendations: One sample z test, One sample t test, Independent samples t test, Dependent samples t test. (1 point each): 1) A study was performed to test whether cars get better mileage on premium gas than on regular gas. Each of 10 cars was first filled with either regular or premium gas, decided by a coin toss, and the mileage for that tank was recorded. The mileage was recorded again for the same cars using the other kind of gasoline. 2) At the recommendation of a their professor a small group of students decides to test whether the nine-way gourmet peanut butter and jelly sandwich does improve cognitive ability. To test this, the students take the GRE. GRE scores. They then begin a strict 9-way gourmet PB&J diet for one week and re-take the GRE. The students compare both 3) The psychology department at SHSU believes that their graduating students have better memory skills than the rest of the university (after all, they have learned all the tricks to enhancing memory). To test this, the department compares vocabulary scores from the GRE of a sample of psychology students to the average score of SHSU students. 4) A researcher believes that viewing intense high speed movies will increase the viewer's desire to speed on the highway after leaving the theater. The researcher selects a sample, and instructs them to watch Fast and the Furious. The research selects a second sample, and instructs them to watch a nature documentary on ocean life. After watching their respective media, each participant is given a risk-taking assessment. 5) To test the effects of cartoons on cognitive functioning, a researcher assigns 15 children to watch 30 minutes of Spongebob Squarepants, and 15 more children to color for 30 minutes. The research then tests all children on the same cognitive functioning task. 6) A student is curious if she performs better on tests after 5 hours of sleep or after 8 hours of sleep. She records her test scores after getting 5 hours. She then records her test scores after getting 8 hours of sleep. What would be the best test for her to compare these test scores? 7) A study was performed to test eyewitness accuracy. Pairs of participants entered a room believing they would be participating in a gambling experiment. Each participant was given $10 in coins to play poker with. The participants were randomly seated near the door or away from the door. After 15 minutes, an actor dressed in street clothes burst into the room, and stole the money from the participant near the door. The "thief" was later caught, and both participants (the victim and the witness) were asked to identify him in a line-up. Eyewitness accuracies from the participants were then compared. 8) A parakeet breeder believes that she raises healthier parakeets than those bought from pet stores. After contacting the pet stores to determine the average lifespan of store bought parakeets, she then determines the average lifespan of a sample of 18 of her own birds. 9) Two bartenders want to know who receives more tips. They each work every Saturday night during a month and compare their average earnings to determine who makes more money. What type of test should they run? 10) A current popular game relies on the rolling of twenty sided dice to determine success or failure. The current iteration occasionally uses rolling two dice, but only selecting the best roll to determine the outcome. An older edition merely modified the roll by 2 during these occasions. A sample of 20 rolls under the new convention has been collected, and is compared against 13.5 (the distribution mean of the old convention)