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Finding the Fourth Proportional to 645.31, 890.54 and 379.81

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Solution

The fourth proportional to 645.31, 890.54 and 379.81 is: 524.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.31 : 890.54 = 379.81 : x
  2. Step 2: Convert to fraction form
    645.31/890.54 = 379.81/x
  3. Step 3: Cross multiply
    645.31x = 890.54 × 379.81
  4. Step 4: Simplify right side
    645.31x = 338,236.00
  5. Step 5: Solve for x
    x = 338,236.00/645.31
  6. Step 6: Final answer
    x = 524.14

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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.