Answer:
The expected total amount of time the operator will spend on the calls each day is of 210 minutes.
Step-by-step explanation:
Normal Probability Distribution:
Problems of normal distributions can be solved using the z-score formula.
In a set with mean
and standard deviation
, the z-score of a measure X is given by:

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.
n-values of normal variable:
Suppose we have n values from a normally distributed variable. The mean of the sum of all the instances is
and the standard deviation is 
Calls to a customer service center last on average 2.8 minutes.
This means that 
75 calls each day.
This means that 
What is the expected total amount of time in minutes the operator will spend on the calls each day
This is M, so:

The expected total amount of time the operator will spend on the calls each day is of 210 minutes.
Get like terms together. you might have to move across the equals sign
3x-x=-6+82
2x=76
x=38
Answer:
90 hardcover books
Step-by-step explanation:
We can solve this by setting up a couple of equations.
Let's allow x to represent the number of paperbacks Tim owns, and allow y to represent the number of hardcover books he owns.
Using the information in the question, we can write the equations:
1)x = 4y-3
2) x+y=447
Let's rearrange equation 1 so that it is in standard form:
x-4y=-3
And then let's multiply equation 2 by 4 so that we can cancel out y when we solve the system of equations:
4(x+y=447)
4x+4y=1,788
Then we can add the two equations and solve for x:
1) x-4y=-3
+ 2)4x+4y=1,788
------------------------------------
5x=1,785
x=357
So now we now the number of paperback books Tim has is 357. Let's plug this into one of the original equations to solve for the number of hardcover books (y):
357+y=447
y=90
And now we know that Tim owns 90 hardcover books.
The answer is B you jump -5
Answer:
Step-by-step explanation:
(4x+3)²÷(x-10)
=(16x²+24x+9)÷(x-10)
x-10) 16x²+24x+9 (16x+184
16x²-160x
- +
------------------
184x+9
184x-1840
- +
----------------
1849
----------------