Answer: He is not correct.
Steps:
Let x1 and x2 be the first and second number, respectively.
In words, if the second is 125%, or 5/4 of the first number (first equation),
then the first is 4/5 of the second, which is 0.8 or 80%.
it is the measurement of the positions, motions, and magnitudes of stars.
We can adjust the data by adding 4 to everything before we calculate the statistics. Or we can calculate the statistics on the given data and just add 4 to everything at the end. We'll get the same answer either way.
Let's sort the seven data points: 5 5 5 7 7 9 10
Those add up to 48 so the mean is 48/7 = 6.9
The one in the middle is 7 so the median = 7
The mode is the most common one, mode = 5
The range is the difference between max and min, so range = 10 - 5 = 5
In the second week we add four to everything. Since that adds four to the min and max, the range doesn't change.
Answer: mean=10.9, median=11, mode=9, range=5
the little check with the dash on top