Answer:
The minimum average cost is $643.75
It should be built 62.5 machines to achieve the minimum average cost
Step-by-step explanation:
The equation that represents the cost C to produce x DVD/BLU-ray players is C = 0.04x² - 5x + 800
To find the minimum cost differentiate C to equate it by 0 to find the average cost per machine and to find the value of the minimum cost
∵ C = 0.04x² - 5x + 800
- Differentiate C with respect to x
∴ 
∴ 
- Equate
by 0
∴ 0.08x - 5 = 0
- Add 5 to both sides
∴ 0.08x = 5
- Divide both sides by 0.08
∴ x = 62.5
That means the minimum average cost is at x = 62.5
Substitute the value of x in C to find the minimum average cost
∵ C = 0.04(62.5)² - 5(62.5) + 800
∴ C = 643.75
∵ C is the average cost
∴ The minimum average cost is $643.75
∵ x is the number of the machines
∴ It should be built 62.5 machines to achieve the minimum
average cost
These 4 options are correct.
10 x 10 = 100
20 + 20 + 20 + 20 +20 = 100
4 x 25 = 100
Answer:
a) 
b) 
And replacing we got:

c) 


And adding we got:

Step-by-step explanation:
Previous concepts
The binomial distribution is a "DISCRETE probability distribution that summarizes the probability that a value will take one of two independent values under a given set of parameters. The assumptions for the binomial distribution are that there is only one outcome for each trial, each trial has the same probability of success, and each trial is mutually exclusive, or independent of each other".
Solution to the problem
Let X the random variable of interest, on this case we now that:
The probability mass function for the Binomial distribution is given as:
Where (nCx) means combinatory and it's given by this formula:
Assuming the following questions:
a. exactly five
For this case we can use the probability mass function and we got:

b. at least one
For this case we want this probability:

And we can use the complement rule and we got:


And replacing we got:

c. between four and six, inclusive.
For this case we want this probability:




And adding we got:

Answer:
6.5e^(i·(-157.38°)) ≈ 6.5e^(-2.7468i)
Step-by-step explanation:
A suitable calculator can find the value of this ratio for you.
((2+3i)/(1-i))² = -6 -2.5i ≈ 6.5∠-157.38° ≈ 6.5e^(-2.7468i)
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The second attachments shows the calculator set to radian mode for the angle measure.