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Finding the Fourth Proportional to 621.74, 856.98 and 455.69

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Solution

The fourth proportional to 621.74, 856.98 and 455.69 is: 628.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    621.74 : 856.98 = 455.69 : x
  2. Step 2: Convert to fraction form
    621.74/856.98 = 455.69/x
  3. Step 3: Cross multiply
    621.74x = 856.98 × 455.69
  4. Step 4: Simplify right side
    621.74x = 390,519.36
  5. Step 5: Solve for x
    x = 390,519.36/621.74
  6. Step 6: Final answer
    x = 628.10

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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.