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Finding the Fourth Proportional to 455.80, 628.72 and 287.86

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Solution

The fourth proportional to 455.80, 628.72 and 287.86 is: 397.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    455.80 : 628.72 = 287.86 : x
  2. Step 2: Convert to fraction form
    455.80/628.72 = 287.86/x
  3. Step 3: Cross multiply
    455.80x = 628.72 × 287.86
  4. Step 4: Simplify right side
    455.80x = 180,983.34
  5. Step 5: Solve for x
    x = 180,983.34/455.80
  6. Step 6: Final answer
    x = 397.07

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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.