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Finding the Fourth Proportional to 640.72, 884.28 and 378.78

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Solution

The fourth proportional to 640.72, 884.28 and 378.78 is: 522.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    640.72 : 884.28 = 378.78 : x
  2. Step 2: Convert to fraction form
    640.72/884.28 = 378.78/x
  3. Step 3: Cross multiply
    640.72x = 884.28 × 378.78
  4. Step 4: Simplify right side
    640.72x = 334,947.58
  5. Step 5: Solve for x
    x = 334,947.58/640.72
  6. Step 6: Final answer
    x = 522.77

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1.5x scale

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.