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Finding the Fourth Proportional to 645.90, 891.49 and 384.06

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Solution

The fourth proportional to 645.90, 891.49 and 384.06 is: 530.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.90 : 891.49 = 384.06 : x
  2. Step 2: Convert to fraction form
    645.90/891.49 = 384.06/x
  3. Step 3: Cross multiply
    645.90x = 891.49 × 384.06
  4. Step 4: Simplify right side
    645.90x = 342,385.65
  5. Step 5: Solve for x
    x = 342,385.65/645.90
  6. Step 6: Final answer
    x = 530.09

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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.