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Finding the Fourth Proportional to 561.40, 840.73 and 387.58

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Solution

The fourth proportional to 561.40, 840.73 and 387.58 is: 580.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    561.40 : 840.73 = 387.58 : x
  2. Step 2: Convert to fraction form
    561.40/840.73 = 387.58/x
  3. Step 3: Cross multiply
    561.40x = 840.73 × 387.58
  4. Step 4: Simplify right side
    561.40x = 325,850.13
  5. Step 5: Solve for x
    x = 325,850.13/561.40
  6. Step 6: Final answer
    x = 580.42

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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.