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Finding the Fourth Proportional to 630.38, 870 and 381.78

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Solution

The fourth proportional to 630.38, 870 and 381.78 is: 526.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    630.38 : 870 = 381.78 : x
  2. Step 2: Convert to fraction form
    630.38/870 = 381.78/x
  3. Step 3: Cross multiply
    630.38x = 870 × 381.78
  4. Step 4: Simplify right side
    630.38x = 332,148.60
  5. Step 5: Solve for x
    x = 332,148.60/630.38
  6. Step 6: Final answer
    x = 526.91

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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.