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:



The value of root 10 is between 3 and 3.5
Answer:
$7.76 per hour.
Step-by-step explanation:
Multiply 8 by 3.1%, or .031. Subtract that total from the amount currently being paid. Voila!
Answer:
20%
Step-by-step explanation:
1/5 of 1 hour = 20 minutes
so 1/5 = 20%
25% + 20% = 45%
0.35 = 35%
45% + 35% = 80%
100% - 80% = 20%
Answer = 20%
Hope this helps!
Answer:
120
Step-by-step explanation:
solve for x then substitute