Answer:
A = 
Step-by-step explanation:
Area of a circle is:
A = πr²
We are given a radius of 20 cm.
A = πr²
A = π(20)²
A = π400
<em>A = 400πcm²</em>
Hope this helps.
Answer:
don't know sorry
Step-by-step explanation:
dont know sorry
Answer:
a) 
With:


b) 

c) 

d) 


Step-by-step explanation:
For this case we know the following propoertis for the random variable X

We select a sample size of n = 81
Part a
Since the sample size is large enough we can use the central limit distribution and the distribution for the sampel mean on this case would be:

With:


Part b
We want this probability:

We can use the z score formula given by:

And if we find the z score for 89 we got:


Part c

We can use the z score formula given by:

And if we find the z score for 75.65 we got:


Part d
We want this probability:

We find the z scores:



Answer:
Statement 1. P
Reason 1. Theorem: The measure of an external angle of a triangle is equal to the sum of the measures of the remote interior angles.
Statement 2. 132 = 3x + 54
Statement 3. x = 26
Answer:
Step-by-step explanation:
5x + y = 9
-10x + 7y = 18
10x + 2y = 18
-10x + 7y = 18
9y = 36
y = 4
5x + 4 = 9
5x = 5
x = 1
(1,4)
answer is D