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Finding the Fourth Proportional to 645.90, 890.80 and 468.87

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Solution

The fourth proportional to 645.90, 890.80 and 468.87 is: 646.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.90 : 890.80 = 468.87 : x
  2. Step 2: Convert to fraction form
    645.90/890.80 = 468.87/x
  3. Step 3: Cross multiply
    645.90x = 890.80 × 468.87
  4. Step 4: Simplify right side
    645.90x = 417,669.40
  5. Step 5: Solve for x
    x = 417,669.40/645.90
  6. Step 6: Final answer
    x = 646.65

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.