Suppose that memory for unrelated words is distributed normally with a mean of µ = 60. A random sample of n =36 is selected from this population. After a treatment is administered to the individuals in the sample, a memory test that measures memory for unrelated words is administered, the sample mean is found to be M = 52. If the population standard deviation is σ = 18, can we conclude that the treatment has a significant effect? Use a two-tailed test with α=.05. The alternative hypothesis in words is

Which of the following best reflects what we know about how the flu virus moves between species? a) the flu virus in a pig is mutated and replicated in alternate arrangements so that humans who eat the pig products can be infected. b) a flu virus from a human epidemic or pandemic infects birds; the birds replicate the virus differently and then pass it back to humans. c) an influenza virus gains new sequences of dna from another virus, such as a herpesvirus; this enables it to be transmitted to a human host. d) an animal such as a pig is infected with more than one virus, genetic recombination occurs, the new virus mutates, the virus is passed to a new species such as a bird, and the virus mutates again and can now be transmitted to humans.