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Finding the Fourth Proportional to 458.80, 687.90 and 215.68

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Solution

The fourth proportional to 458.80, 687.90 and 215.68 is: 323.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    458.80 : 687.90 = 215.68 : x
  2. Step 2: Convert to fraction form
    458.80/687.90 = 215.68/x
  3. Step 3: Cross multiply
    458.80x = 687.90 × 215.68
  4. Step 4: Simplify right side
    458.80x = 148,366.27
  5. Step 5: Solve for x
    x = 148,366.27/458.80
  6. Step 6: Final answer
    x = 323.38

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.