The scale of a map is 2 cm : 21 km. find the actual distance for 9 cm on the map.
2 answers:
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Answer: 8788
Step-by-step explanation:
Use the formula and use 3 for pi
13cm is the radius
= 2197
2197 x 3 = 6591
6591 x 4/3 = 8788
9514 1404 393
Answer:
e(w) = -40w^2 +400w +20
Step-by-step explanation:
A graphing calculator or spreadsheet can do the quadratic regression and help you find the formula. Here earnings (e) as a function of weeks (w) can be expressed by ...
e(w) = -40w^2 +400w +20
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<em>Further development</em>
There are a couple of other ways you can go at this. One is to write equations for a, b, c using the standard form quadratic.
aw^2 +bw +c = e
a +b +c = 380 . . . . . . for week 1
4a +2b +c = 660 . . . for week 2
9a +3b +c = 860 . . . for week 3
The solution of this system of equations will give the coefficients of the quadratic. Your graphing calculator or any of several web sites can solve these equations for you.
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Consider the differences between quadratic values for w = 1, 2, 3.
e2 -e1 = (4a +2b +c) -(a +b +c) = 3a +b
e3 -e2 = (9a +3b +c) -(4a +2b +c) = 5a +b
Then the second differences are ...
(e3 -e2) -(e2 -e1) = (5a +b) -(3a +b) = 2a
In the given set of numbers, the first differences are ...
660 -380 = 280 . . . . . . . call this d1
860 -660 = 200
And the second difference is ...
200 -280 = -80 . . . . . . . call this d2
From the above, we know that 2a = -80 ⇒ a = -40
and 3a +b = 280 = 3(-40) +b ⇒ b = 400
Finally, a+b+c = 380 = -40 +400 +c ⇒ c = 20
Then the generic solution is ...
a = d2/2
b = d1 -3a
c = e1 -a -b . . . . . where e1 is the first-week's earnings
To find the number of males from the new sample, we first need to compute for the z-score as shown below.
where Χ is the mean height we want to check, μ is the expected mean of the height, δ is the standard deviation, and n is the number of samples. Since, we have all of these information at hand, we can now compute for the z-score of the sample.
Now, using the z-table, we can find its p-value which we'll be using to find the number of males. Since z-score is -1, we have P(z > <span>0.158655) = 1 - 0.158655 = 0.841345.
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This signifies the percent of the total population that has a height of more than 164. So, out of 1200, we have 0.841345(1200) = 1009.614 ≈ 1010.
Therefore, we've seen that there are approximately 1010 male from the sample that will have a height of more than 164.
Answer: 1010
where Χ is the mean height we want to check, μ is the expected mean of the height, δ is the standard deviation, and n is the number of samples. Since, we have all of these information at hand, we can now compute for the z-score of the sample.
Now, using the z-table, we can find its p-value which we'll be using to find the number of males. Since z-score is -1, we have P(z > <span>0.158655) = 1 - 0.158655 = 0.841345.
</span>
This signifies the percent of the total population that has a height of more than 164. So, out of 1200, we have 0.841345(1200) = 1009.614 ≈ 1010.
Therefore, we've seen that there are approximately 1010 male from the sample that will have a height of more than 164.
Answer: 1010