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Finding the Fourth Proportional to 476.20, 656.40 and 388.72

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Solution

The fourth proportional to 476.20, 656.40 and 388.72 is: 535.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    476.20 : 656.40 = 388.72 : x
  2. Step 2: Convert to fraction form
    476.20/656.40 = 388.72/x
  3. Step 3: Cross multiply
    476.20x = 656.40 × 388.72
  4. Step 4: Simplify right side
    476.20x = 255,155.81
  5. Step 5: Solve for x
    x = 255,155.81/476.20
  6. Step 6: Final answer
    x = 535.82

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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.