Match each equation with the number that makes it true.
2 answers:
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Answer:
Step-by-step explanation:
Begin with the standard form of a circle as a conic:
For a circle, A and C will be the exact same, and B will equal 0. If B is non-zero, the equation represents a rotation of a conic, which is reserved for college-level courses. Shortening this, then:
is good enough for us for this. Start with the first point on the circle, (2, 31) and fill in the equation above with x and y:
which simplifies down to:
Do the same with the next point on the circle, (-15, 14):
which simplifies down to:
Do the same with the last point, (33, 0):
which simplifies down to:
Now we will add (1) and (2) to get (4):
2D + 31E + F = -965
-15D + 14E + F = -421
Multiply the top equatio by -1 to get rid of the F terms:
-2D - 31E - F = 965
-15D + 14E + F = -421
which simplifies to
(4): -17D - 17E = 544
Now add (2) and (3) to get (5):
-15D + 14E + F = -421
33D + F = -1089
Multiply the bottom equation by -1 to get rid of the F terms:
-15D + 14E + F = -421
-33D - F = 1089
which simplifies to
(5): -48D + 14E = 668
Now add (4) and (5) together and eliminate the E terms:
-17D - 17E = 544
-48D + 14E = 668
In order to eliminate the E terms, multiply the top equation by 14 and the bottom equation by 17 to solve for D:
-238D - 238E = 7616
-816D + 238E = 11356
Which gives you that
D = -18
Now plug the value for D into (4) to find E:
-17(-18) - 17E = 544 and
306 - 17E = 544 and
-17E = 238 so
E = -14
Now plug the values for both D and E into (1) to find F:
2(-18) + 31(-14) + F = -965 and
-36 - 434 + F = -965 and
-470 + F = -965 so
F = -495
Now we can fill in the standard form of the conic:
but we're not done til we complete the square on both the x terms and the y terms (and I am assuming you know how to complete the square):
which simplifies to
The second choice down matches that equation, but the center they have there is not correct. The center of that circle is (9, 7) and they have it as being (7, 10) with a radius of 5. The radius is 25. The center is wrong in the equation that represents the circle as is the radius. Maybe let someone know that...
Answer:
And we can use the following code to find it "=NORM.DIST(-1.279,0,1,TRUE)"
Step-by-step explanation:
Assuming this complete problem: "The CEO of a software company is committed to expanding the proportion of highly qualified women in the organization's staff of salespersons. He believes that the proportion of women in similar sales positions across the country is less than 45%. Hoping to find support for his belief, he directs you to test
H0: p .45 vs H1: p < .45.
In doing so, you collect a random sample of 50 salespersons employed by his company, which is thought to be representative of sales staffs of competing organizations in the industry. The collected random sample of size 50 showed that only 18 were women.
Compute the p-value associated with this test. Place your answer, rounded to 4 decimal places, in the blank. For example, 0.3456 would be a legitimate entry."
1) Data given and notation
n=50 represent the random sample taken
X=18 represent the number of women in the sample selected
estimated proportion of women in the sample
is the value that we want to test
represent the significance level
z would represent the statistic (variable of interest)
represent the p value (variable of interest)
2) Concepts and formulas to use
We need to conduct a hypothesis in order to test the claim that the proportion of women is less than 0.45:
Null hypothesis:
Alternative hypothesis:
When we conduct a proportion test we need to use the z statistic, and the is given by:
(1)
The One-Sample Proportion Test is used to assess whether a population proportion is significantly different from a hypothesized value
.
3) Calculate the statistic
Since we have all the info requires we can replace in formula (1) like this:
4) Statistical decision
It's important to refresh the p value method or p value approach . "This method is about determining "likely" or "unlikely" by determining the probability assuming the null hypothesis were true of observing a more extreme test statistic in the direction of the alternative hypothesis than the one observed". Or in other words is just a method to have an statistical decision to fail to reject or reject the null hypothesis.
The next step would be calculate the p value for this test.
Since is a left tailed test the p value would be:
And we can use the following code to find it "=NORM.DIST(-1.279,0,1,TRUE)"