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Finding the Fourth Proportional to 455.60, 687.02 and 405.20

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Solution

The fourth proportional to 455.60, 687.02 and 405.20 is: 611.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    455.60 : 687.02 = 405.20 : x
  2. Step 2: Convert to fraction form
    455.60/687.02 = 405.20/x
  3. Step 3: Cross multiply
    455.60x = 687.02 × 405.20
  4. Step 4: Simplify right side
    455.60x = 278,380.50
  5. Step 5: Solve for x
    x = 278,380.50/455.60
  6. Step 6: Final answer
    x = 611.02

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.