The following answer is:
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Hope this helps!</span></span>
Answer:

Step-by-step explanation:
Let X be the number of units produced, and P be the cost of production.
#Given that 
Cost of production can be calculated as:

#Mean of the total cost is calculated as;

Hence, the mean cost of production is $2,000
#Variance of the total cost is calculated as;

Hence, the variancecost of production is $3,600
80 pages in 2 hours is the same as 40 pages in 1 hour or ≈ 0.677 in 1 minute