Ball falls so that its distance above ground can be modeled by the equation s
=
−
16
t
2
+
100
s=−16t
2
+100 , where
s
s is the distance above the ground in feet and
t
t represents time in seconds. According to this model, how many seconds does it take for the ball to hit the ground? Round to the nearest tenth if necessary.

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