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Finding the Fourth Proportional to 686.18, 947.85 and 653.78

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Solution

The fourth proportional to 686.18, 947.85 and 653.78 is: 903.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    686.18 : 947.85 = 653.78 : x
  2. Step 2: Convert to fraction form
    686.18/947.85 = 653.78/x
  3. Step 3: Cross multiply
    686.18x = 947.85 × 653.78
  4. Step 4: Simplify right side
    686.18x = 619,685.37
  5. Step 5: Solve for x
    x = 619,685.37/686.18
  6. Step 6: Final answer
    x = 903.09

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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.