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Finding the Fourth Proportional to 840.70, 1,259.72 and 579.81

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Solution

The fourth proportional to 840.70, 1,259.72 and 579.81 is: 868.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    840.70 : 1,259.72 = 579.81 : x
  2. Step 2: Convert to fraction form
    840.70/1,259.72 = 579.81/x
  3. Step 3: Cross multiply
    840.70x = 1,259.72 × 579.81
  4. Step 4: Simplify right side
    840.70x = 730,402.25
  5. Step 5: Solve for x
    x = 730,402.25/840.70
  6. Step 6: Final answer
    x = 868.80

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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.