Aschool district decides to compare a new math textbook to the textbook that has been in use for the past few years. each of the fourth graders in one school is assigned to be in one of two classes, one in which a teacher continues using the old book and another in which a new teacher uses the new book. the school administrators compare the average scores of the two classes on a mathematics standardized test at the end of the year to determine which book is better. which of the following is a potential confound in this study?

What is the social order of the ancient river valley civilization of mesopotamia?

Mankiw attributes – chapter 1 and his 10 principles – differences in living standards within a countryover time and across countries at a moment in time to: a. the presence or absence of inflation and unemployment. b. the allocation of resources between private markets and the public sector. c. those that have dealt successfully with the efficiency v. equality tradeoff and those that haven’t. d. differences in productivity. e. ones that think at the margin and respond to incentives and those that don’t.

Athief was passing by a house under construction when he noticed that the ladder being used by workers on the roof had copper braces supporting the rungs. after making sure that the workers on the roof could not see him, the thief used pliers that he had in his pocket to remove all of the copper braces that he could reach from the ground. a short time later, a worker climbed down the ladder and it collapsed. he fell to the ground and severely injured his back. the thief was apprehended a few hours later trying to sell the copper for scrap. a statute in the jurisdiction makes it a felony for "maliciously causing serious physical injury to another." the thief was charged with malicious injury under the statute and was also charged with larceny. after a jury trial in which the above facts were presented, he was convicted of both charges. if he appeals the conviction for the malicious injury charge on grounds of insufficient evidence, how should the court rule? a affirm the conviction, because the thief was engaged in criminal conduct at the time of the act that resulted in the injury. b affirm the conviction, because the jury could have found that the thief acted with malice. c reverse the conviction, because there was no evidence that the thief intended to injure anyone. d reverse the conviction, because there was no evidence that the thief bore any malice towards the workers on the roof.