Answer:
first question: decrease - second question: 34
Step-by-step explanation:
first question: to find the mean, you need to add all of the numbers together and divide the sum of those by the amount of numbers you added together. in this question, it would be
73+79+96+84=332 -> 332/4=83 is the mean for the 1st set of numbers
(1) (2) (3) (4)
the question asks what happens after the next test score is added in, for this, you will do the same steps as before except you add in the 80 for her fifth test and then divide by 5 instead of 4, because you have another number being added.
73+79+96+84+80=412 -> 412/5=82.4 is the mean for the 2nd set of numbers
the second set of numbers, after the fifth test score is added in, is lower than the first set of numbers. therefore, the mean decreases
second question: same concept, except on a dot plot. a dot above a number means that there is one of those numbers that should be counted. this means since there are 2 dots above the 30, there are 2 30s being added to the rest of the numbers. in this dot plot, the numbers being added are
30+30+32+32+34+38+38+38=272 -> 272/8=34 is the mean
hope this helps!
