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Finding the Fourth Proportional to 879.56, 1,320.71 and 840.60

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Solution

The fourth proportional to 879.56, 1,320.71 and 840.60 is: 1,262.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    879.56 : 1,320.71 = 840.60 : x
  2. Step 2: Convert to fraction form
    879.56/1,320.71 = 840.60/x
  3. Step 3: Cross multiply
    879.56x = 1,320.71 × 840.60
  4. Step 4: Simplify right side
    879.56x = 1,110,188.34
  5. Step 5: Solve for x
    x = 1,110,188.34/879.56
  6. Step 6: Final answer
    x = 1,262.21

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.