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:
possible answers below!
Step-by-step explanation:
if they are vertical angles then the measure of ZB is 78
if they are supplementary then ZB is 102 degrees
if they are complementary then ZB is 12 degrees
It depends on where its located, cant really help if i dont have a pic..but i hope this helps! :)
You have troubles with domains only if you have:
- Denominators
- Roots with an even degree
- Logarithms
In this case, you have neither of these three, so you can compute your function wherever you want. The domain is all real numbers.