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| PROBLEM
2: CONTINUOUS DISTRIBUTIONS |
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| 6.65 |
According to Editor and
Publisher Yearbook, |
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the average daily
circulation of The Wall |
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Street Journal based on 1994
figures |
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is 1,818,562. |
The standard deviation |
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is 50,940. Assume the paper's daily circulation |
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is normally
distributed. On what percentage |
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of days would it surpass a
circulation |
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of 1,850,000? Suppose the paper cannot |
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support the fixed
expenses of a full-production |
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set-up if the circulation
drops below 1,700,000. |
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If the probability of
this event occuring is low, |
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the production manager
might try to keep the |
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full crew in place and
not disrupt operations. |
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How often will this event
happen, based on the |
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historical information? |
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| SOLUTION: |
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m = |
1,818,562/day |
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s = |
50,940 |
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Z1 = |
1,850,000-1,818,562 |
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Z2 = |
1,700,000-1,818,562 |
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50,940 |
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50,940 |
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Z1 = |
0.6172 |
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Z2 = |
-2.32748 |
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P1 = |
0.2324 |
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P2 = |
0.4901 |
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Pa = |
0.5 - 0.2324 |
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Pb = |
0.5 - 0.4901 |
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Pa = |
0.2676 |
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Pb = |
0.0099 |
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