Asimple random sample of 1000 american adults found that the average number of hours spent watching television during a typical week was 13.8. a simple random sample of 500 canadians yielded an average of 12.5 hours per week of television viewing. assume that the american and canadian distributions for weekly television, viewing times have the same standard deviations. the sampling variability associated with the sample means (described above) is

There are two major tests of readiness for college: the act and the sat. act scores are reported on a scale from 1 to 36. the distribution of act scores in recent years has been roughly normal with mean µ = 20.9 and standard deviation s = 4.8. sat scores are reported on a scale from 400 to 1600. sat scores have been roughly normal with mean µ = 1026 and standard deviation s = 209. reports on a student's act or sat usually give the percentile as well as the actual score. the percentile is just the cumulative proportion stated as a percent: the percent of all scores that were lower than this one. tanya scores 1260 on the sat. what is her percentile (± 1)?