Answer:
C) 2
Step-by-step explanation:
step 1: Find mean of data set
2+4+4+5+7+8 = 30
30/6 = 5
Mean = 5
step 2: subtract each data value from the mean and square it
5-2 = 3; 3² = 9
5-4 = 1; 1² = 1
5-4 = 1; 1² = 1
5-5 = 0; 0² = 0
5-7 = -2; (-2²) = 4
5-8 = -3; (-3²) = 9
Add the squared results:
9+1+1+0+4+9 = 24
Divide 24 by 6 to get the Variance of 4
Take the square root of the Variance to get the Standard Deviation
= 2
First Question:
Number of trapezoids - 6
Perimeter - 72
3 + 3 + 3 + 6 = <u>15</u>
3 + 3 + 3 + 3 + 6 + 6 = <u>24</u>
3 + 3 + 6 + 3 + 3 + 6 + 3 + 6 = <u>33</u>
15 + 24 + 33 = <u>72</u>
Second Question:
Number of cubes - 6
Surface area - 24 (probably 480 since it said <em>area</em>)
first cube - 6 ones
second cube - 8 ones
Third cube - 10 ones
you could do 6 + 8 + 10 = 24 or add up all the ones (1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1) and you will still get 24
(It said <em>area</em>, and area means to multiply so maybe its 6 x 8 x 10 = 480 and not 6 + 8 + 10)
Anyways have a good day/night :) I might be wrong, but I hope I helped at least a little
Answer:
Step-by-step explanation 10 + 2.50d = 850
David starts with $10 and each day he earns $2.50. The d represents a variable and can be any number.
To find d you must solve the equation.
10 + 2.50d = 850
2.50d = 840 (subtract 10 from 850)
d = 336 (divide 840 by 2.50)
It will take David 336 days to save $850.
It will cost atleast 78 dollars
9) Because the total number of pencils is 180 and you will use them up in 30 days, the equation will have to equal 0 total pencils when 30 is substituted in for the time factor, or x. This already takes our choice 3 because it doesn’t meet this criteria.
The answer to how many pencils in 20 days could be answered by plugging in 20 for x. Choice 4 cannot work because it results in a negative number of pencils. Choices 1 and 2 use the same equation, so by plugging in 20 it is clear choice 2 is the correct answer.
10) A line parallel to the go en equation would have the same slope, -3, which means choices 1 and 4 are out. Plug in (-2,5) into both choices 2 and 3. Plugging -2 into x in choice 2 gives -5, and in choice 3 gives 5 for the y value. Therefore choice 3 is correct.
