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Finding the Fourth Proportional to 645.91, 891.50 and 384.08

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Solution

The fourth proportional to 645.91, 891.50 and 384.08 is: 530.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.91 : 891.50 = 384.08 : x
  2. Step 2: Convert to fraction form
    645.91/891.50 = 384.08/x
  3. Step 3: Cross multiply
    645.91x = 891.50 × 384.08
  4. Step 4: Simplify right side
    645.91x = 342,403.82
  5. Step 5: Solve for x
    x = 342,403.82/645.91
  6. Step 6: Final answer
    x = 530.11

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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.