Answer:
30
Step-by-step explanation:
Answer:


And then the percentage between 24 and 40 would be 
Step-by-step explanation:
For this problem we have the following parameters given:

And for this case we want to find the percentage of lightbulb replacement requests numbering between 24 and 40.
From the empirical rule we know that we have 68% of the values within one deviation from the mean, 95% of the values within 2 deviations and 99.7% within 3 deviations.
We can find the number of deviations from themean for the limits with the z score formula we got:

And replacing we got:


And then the percentage between 24 and 40 would be 
Answer:
The speed of the boat in still water is 10 miles / hour
Step-by-step explanation:
The trip there, and the trip back are the same -- 30 miles
Let the rate of the boat = x
Let the rate of the water = y
30 = 2*(x + y)
30 = 6*(x - y)
Divide the top equation by 2
Divide the bottom equation by 6
15 = x + y
<u>5 = x - y </u> Add the equations together.
20 = 2x Divide by 2
20/2 = x
x = 10
Answer:
Answer is on pic
Step-by-step explanation:
I hope it's helpful!