Answer:
The absolute error is <u>4 ft</u> and percent error of Tony's estimate is <u>9.8%</u>.
Step-by-step explanation:
Given:
Tony estimated the height of his office building to be 45ft. The actual height of his office building is 41ft.
Now, to find the absolute error and the percent error of Tony's estimate.
The height of his office building = 45ft.
The actual height of his office building = 41 ft.
So, to get the absolute error:
<em>The height of his office building - the actual height of his office building</em>

The absolute error = 4 ft.
Now, to get the percent error of Tony's estimate:



<em>Percent error of Tony's estimate rounding to nearest tenth = 9.8%.</em>
Therefore, the absolute error is 4 ft and percent error of Tony's estimate is 9.8%.
For this problem you can create a proportion.
Since 31,100 copies is 7.8% of the total copies spoke up to date you can make this proportion:
31,100. 7.8%
——— =. ———
x. 100%
Now you cross multiply and you will get
7.8x=3,110,000
After this you solve for x by isolating the variable.
7.8x/7.8. 3,110,000/7.8
x=398,717.949
Since the question asks you to round to the nearest whole number which is 7 then the final answer would be 398,718
Answer: There has been 398,718 copies sold to date.
Is there supposed to be more to the question or?
1/8 + 3/4 = 1/8 + 6/8 = 7/8 (to the right)
1/8 - 3/4 = 1/8 - 6/8 = -5/8 (to the left)
Answers are 7/8 and -5/8.