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Finding the Fourth Proportional to 686.44, 945.12 and 621.64

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Solution

The fourth proportional to 686.44, 945.12 and 621.64 is: 855.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    686.44 : 945.12 = 621.64 : x
  2. Step 2: Convert to fraction form
    686.44/945.12 = 621.64/x
  3. Step 3: Cross multiply
    686.44x = 945.12 × 621.64
  4. Step 4: Simplify right side
    686.44x = 587,524.40
  5. Step 5: Solve for x
    x = 587,524.40/686.44
  6. Step 6: Final answer
    x = 855.90

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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.