= (-3 – (-2))+ (1 - (-4))

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

Find the distance between the pair of points a(-1,8) and b(-8,4)

Two years ago a man was six times as old as his daughter. in 18 years he will be twice as old as his daughter. determine their present ages.