Use the proportion to find the missing dimension of the original rectangle. 1. Set up the proportion: StartFraction x over three-fifths EndFraction = StartFraction 20 over 12 EndFraction 2. Use cross products: 12(x) = 20(3 5 ) 3. Simplify: 12x = 4. Divide: x =

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