Which expression is equivalent to the following complex fraction? StartFraction 1 Over x EndFraction minus StartFraction 1 Over y EndFraction divided by StartFraction 1 Over x EndFraction + StartFraction 1 Over y EndFraction
StartFraction y + x Over y minus x EndFraction
StartFraction (y minus x) (y + x) Over x squared y squared EndFraction
StartFraction x squared y squared Over (y + x) (y + x) EndFraction
StartFraction y minus x Over y + x EndFraction

Ur environment is very sensitive to the amount of ozone in the upper atmosphere. the level of ozone normally found is 4.04.0 parts/million (ppm). a researcher believes that the current ozone level is not at a normal level. the mean of 2525 samples is 4.44.4 ppm with a standard deviation of 0.80.8. assume the population is normally distributed. a level of significance of 0.020.02 will be used. make the decision to reject or fail to reject the null hypothesis. answer tables