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Finding the Fourth Proportional to 640.78, 956.50 and 550.06

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Solution

The fourth proportional to 640.78, 956.50 and 550.06 is: 821.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    640.78 : 956.50 = 550.06 : x
  2. Step 2: Convert to fraction form
    640.78/956.50 = 550.06/x
  3. Step 3: Cross multiply
    640.78x = 956.50 × 550.06
  4. Step 4: Simplify right side
    640.78x = 526,132.39
  5. Step 5: Solve for x
    x = 526,132.39/640.78
  6. Step 6: Final answer
    x = 821.08

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.