In order to determine if two sets of data are significantly from each other, standard deviations are compared via f-test, and means are compared via t-test. the following data gave the recovery of bromide from spiked samples of vegetable matter, measured by using a gas-liquid chromatographic method. the same amount of potassium bromide was added to each specimen. does the sample matrix interfere in the precision of the method? does the sample matrix interfere in the recoveries? the following percentage recoveries were obtained in a comparison between a new method and the official method of determining oxyphenbutazone. does the mean result obtained by the two methods differ significantly?

The earth's moon is unusually large. two popular theories of the moon's origin include the "sister world" hypothesis, which states that the moon formed from the same materials as the earth, near enough to the earth that they fell into orbit around each other. a second theory is the "capture" hypothesis, in which the moon formed elsewhere in the solar system, and the earth's gravity pulled it into its orbit. studies of what the moon is made of indicate that some of its materials had to come from the earth or from the same area of the solar system where the earth had formed. at the same time, the moon does not contain much of the material that makes up the earth's core, so the moon could not have formed from the same materials as the earth. how do the two facts above affect the described theories of the moon's origin? a. they show that scientists will never agree on where the moon came from. b. they show that more experiments on moon formation need to be done. c. they show that no theory accounts for the existence of the moon. d. they show that neither theory is complete and entirely correct.

Modern weaponry has increased the number of deaths in wars and violent conflicts.

What happens to the temperature of a substance when the average kinetic energy of its particles increases?