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Finding the Fourth Proportional to 621.30, 856.64 and 455.45

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Solution

The fourth proportional to 621.30, 856.64 and 455.45 is: 627.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    621.30 : 856.64 = 455.45 : x
  2. Step 2: Convert to fraction form
    621.30/856.64 = 455.45/x
  3. Step 3: Cross multiply
    621.30x = 856.64 × 455.45
  4. Step 4: Simplify right side
    621.30x = 390,150.13
  5. Step 5: Solve for x
    x = 390,150.13/621.30
  6. Step 6: Final answer
    x = 627.96

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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.