This question will use the Drug effect experiment dataset. here is the link of the dataset: https://www.dropbox.com/s/yik1qn0pfk1ylx4/APPENC12.txt?dl=0

This data set provides results adapted from an experiment in which the effects of a drug on the behaviour of rats were studied. The behaviour under consideration was the rate at which a rat deprived of water presses a lever to obtain water. The experiment was carried out in two parts. Variable 2 identifies the two parts of the study (1, 2).

In Part I of the study, 12 male albino rats of the same strain and approximately the same weight were utilized. Variable 3 identifies each rat (1, .. , , 12). Prior to the experiment, each rat was trained to press a lever for water until a stable rate of pressing was reached. Two factors were studied in this experiment-initial lever press rate (factor A) and dosage of the drug (factor B). The 12 rats were classified into one of three groups according to their initial lever press rate. Variable 4 identifies the level of the initial lever press rate (1, 2, 3). Level 1 is a slow rate, level 2 a moderate rate, and level 3 a fast rate. The levels were defined such that one-third of the rats were classified into each of the three levels.

Four dosage levels of the drug were studied, including a zero level consisting of a saline solution. Variable 5 identifies the drug dosage (1, ... ,4). All dosage levels were specified in terms of milligrams of drug per kilogram of weight of the rat. One hour after a drug dosage injection was administered, an experimental session began during which the rat received water each time after the second lever press. This reinforcement schedule will be denoted by FR-2. Each rat received all four drug dosage levels in a random order. Each of the four drugs dosages were administered twice, thus providing two observation units for each treatment. Variable 6 identifies the observation unit (1, 2).

The response variable was defined as the total number of lever presses divided by the elapsed time (in seconds) during a session for the given treatment. Variable 7 is the response variable.

Consider only Part I of the study and observation unit 1 for each drug dosage level; ie., include only observations for which variable 2 equals 1 and variable 6 equals 1. Treat the 12 rats as subjects and ignore the classification of the rats into the three initial lever press rate groups. Assume that the subjects (rats) have random effects and that the treatments (dosage levels) have fixed effects.

Please also provide the codes, thank you.