To solve this, create an equation that follows 45% of a value is 18. This would look like x*.45=18. Now, solve for x, x*.45=18, divide by .45, x=18/.45=40, making your value 40. To check, plug in your value to the equation 40*.45=18 and see if it stays true.
Range= 4
Range is the highest number minus the lowest number, 10-6=4
Y= -2+21
This is because the slope needs to be the negative reciprocal of 1/2 so the slope is -2 then you take the point (5,11) and plug that an the -2 into y=m(x)+b and you solve for b. In the end you get 21
13. 81.64
14. 803.84
15. 153.83
16. 753.6
you just use circumference and area formulas for a circle
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:


