Select the proper placement for parentheses to speed up the addition for the expression 4 + 6 + 5 a. (5 + 4) + 6 b. (4 + 6) + 5 c. (5 + 6) + 4 d. 4 + (6 + 5)

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