Questions 6 to 10 are related. based on a random sample of n=15 observations, we have obtained a sample mean of x(bar)=1050. the goal is to test: h(0): μ≤1000 and h(a): μ> 1000 assume that x is normally distributed with σ=150. what is the standard error (σ (x bar) )? rounded to two decimal places.

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)?