The other major implication of the Erie doctrine is that federal courts cannot dictate the content of state law when there is no federal issue (and thus no federal supremacy issue) in a case. When hearing claims under state law pursuant to diversity jurisdiction, federal trial courts must apply the statutory and decisional law of the state in which they sit, as if they were a court of that state, even if they believe that the relevant state law is irrational or just bad public policy. And under Erie, deference is one-way only: state courts are not bound by federal interpretations of state law.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): What are states not bound by?
Ah, so.. federal interpretations of state law

Executive vice governor Wei Hong confirmed on November 21, 2008 that more than 90,000 people in total were dead or missing in the earthquake. He stated that 200,000 homes had been rebuilt, and 685,000 were under reconstruction, but 1.94 million households were still without permanent shelter. 1,300 schools had been reconstructed, with initial relocation of 25 townships, including Beichuan and Wenchuan, two of the most devastated areas. The government spent $441 billion on relief and reconstruction efforts.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): How many people did Wei Hong say were dead or missing?
Ah, so.. 90,000

The Paris region hosts France's highest concentration of the grandes écoles – 55 specialised centres of higher-education outside the public university structure. The prestigious public universities are usually considered grands établissements. Most of the grandes écoles were relocated to the suburbs of Paris in the 1960s and 1970s, in new campuses much larger than the old campuses within the crowded city of Paris, though the École Normale Supérieure has remained on rue d'Ulm in the 5th arrondissement. There are a high number of engineering schools, led by the Paris Institute of Technology which comprises several colleges such as École Polytechnique, École des Mines, AgroParisTech, Télécom Paris, Arts et Métiers, and École des Ponts et Chaussées. There are also many business schools, including HEC, INSEAD, ESSEC, and ESCP Europe. The administrative school such as ENA has been relocated to Strasbourg, the political science school Sciences-Po is still located in Paris' 7th arrondissement and the most prestigious university of economics and finance, Paris-Dauphine, is located in Paris' 16th. The Parisian school of journalism CELSA department of the Paris-Sorbonne University is located in Neuilly-sur-Seine. Paris is also home to several of France's most famous high-schools such as Lycée Louis-le-Grand, Lycée Henri-IV, Lycée Janson de Sailly and Lycée Condorcet. The National Institute of Sport and Physical Education, located in the 12th arrondissement, is both a physical education institute and high-level training centre for elite athletes.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): Where is CESLA located?
Ah, so..
Neuilly-sur-Seine