Answer:
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Answer:
The approximate temperature of the pan after it has been away from the heat for 9 minutes is 275.59°F.
Step-by-step explanation:
The formula for D, the difference in temperature between the pan and the room after t minutes is:

Compute the approximate difference in temperature between the pan and the room after 9 minutes as follows:


Then the approximate temperature of the pan after it has been away from the heat for 9 minutes is:
D = P - R
206.59 = P - 69
P = 206.59 + 69
P = 275.59°F
Thus, the approximate temperature of the pan after it has been away from the heat for 9 minutes is 275.59°F.
Answer:
Step-by-step explanation:
From the given information:
the mean 
= 2300
Standard deviation = 
Standard deviation (SD) = 214.4761
TO find:
a) 



From the Z-table, since 5.595 is > 3.999

P(x > 3500) = 0.0001
b)
Here, the replacement time for the mean 
= 0.25
Replacement time for the Standard deviation 

For 115 component, the mean time = (115 × 20)+(114×0.25)
= 2300 + 28.5
= 2328.5
Standard deviation = 
= 
= 
= 
= 
= 214.482
Now; the required probability:




From the Z-table, since 8.376 is > 3.999
P(x > 4125) = 1 - 0.9999
P(x > 4125) = 0.0001
When x=9 the expression is undefined.
That is because any number over 0 is undefined, including 0/0.