a water treatment plant needs to maintain the ph of the water in the reservoir at a certain level. to monitor this, they take 2 oz. of water at 37 locations every hour, measure the ph at each of those locations, and find their average. if the ph level of the reservoir is ok, the results at each location will have varying results, with an average ph of 8.5 and a standard deviation of 0.22. if the ph level of the reservoir is ok, what is the probability that the sample average is less than 8.42?

Mass is the amount of matter in an object.  weight is the measurement of the pull of gravity on an object.  say for example, you travel to the moon which has a different gravitational field compared to the gravitational field of earth. (gravitational fields: earth = 1, moon = 0.165)  now when you are on the moon, the pull of gravity on you is different than on the earth. and as weight is the measurement of the pull of gravity on an object, that means yes, your weight can and will change on the moon.  however, on the moon, on earth or even on jupiter, the amount of mass inside of you remains the same. meaning your physical mass remains constant.  in conclusion it is possible for your weight to change as your mass remains constant. 

0.50 hope this