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Finding the Fourth Proportional to 621.02, 856.68 and 388.28

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Solution

The fourth proportional to 621.02, 856.68 and 388.28 is: 535.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    621.02 : 856.68 = 388.28 : x
  2. Step 2: Convert to fraction form
    621.02/856.68 = 388.28/x
  3. Step 3: Cross multiply
    621.02x = 856.68 × 388.28
  4. Step 4: Simplify right side
    621.02x = 332,631.71
  5. Step 5: Solve for x
    x = 332,631.71/621.02
  6. Step 6: Final answer
    x = 535.62

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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.