Answer:
C
Step-by-step explanation:
the sum of the exterior angles of a polygon = 360°
sum the 4 exterior angles and equate to 360
8x + 9x + 5 + 5x + 4 + 9x + 3 = 360 , that is
31x + 12 = 360 ( subtract 12 from both sides )
31x = 148 ( divide both sides by 31 )
x ≈ 11.23 ( to 2 dec. places )
then exterior angle at B is
9x + 3 = 9(11.23) + 3 ≈ 104° → C
<em>Answer:</em>
<em>The answer is 83</em>
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<em>Hope this helps:3</em>
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The complex solution of a quadratic equation are (- 2 + i ) and
(- 2 - i ).
What is Quadratic equation?
An algebraic equation of the second degree is called a quadratic equation.
Given that;
A quadratic equation is;
3x² = -12x - 15
Now, The equation is written as;
3x² + 12x + 15 = 0
Take 3 common, we get;
3 (x² + 4x + 5) = 0
x² + 4x + 5 = 0
Factorize the equation by using Sridharacharya Formula;
x = - 4 ± √4² - 4*1*5 / 2*1
x = -4 ± √16 - 20 / 2
x = - 4 ± √-4 / 2
Since, √-1 = i
x = -4 ± 2i / 2
x = - 2 ± i
It gives two values of x as;
x = - 2 + i
And, x = - 2 - i
Hence, The complex solution of a quadratic equation are (- 2 + i ) and
(- 2 - i ).
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Answer:
The 80% confidence interval for the the population mean nitrate concentration is (0.144, 0.186).
Critical value t=1.318
Step-by-step explanation:
We have to calculate a 80% confidence interval for the mean.
The population standard deviation is not known, so we have to estimate it from the sample standard deviation and use a t-students distribution to calculate the critical value.
The sample mean is M=0.165.
The sample size is N=25.
When σ is not known, s divided by the square root of N is used as an estimate of σM:

The degrees of freedom for this sample size are:

The t-value for a 80% confidence interval and 24 degrees of freedom is t=1.318.
The margin of error (MOE) can be calculated as:
Then, the lower and upper bounds of the confidence interval are:

The 80% confidence interval for the population mean nitrate concentration is (0.144, 0.186).
Answer:
Step-by-step explanation:
y = kx
If y = 25x , then k = 25