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Finding the Fourth Proportional to 458.55, 687.69 and 215.28

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Solution

The fourth proportional to 458.55, 687.69 and 215.28 is: 322.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    458.55 : 687.69 = 215.28 : x
  2. Step 2: Convert to fraction form
    458.55/687.69 = 215.28/x
  3. Step 3: Cross multiply
    458.55x = 687.69 × 215.28
  4. Step 4: Simplify right side
    458.55x = 148,045.90
  5. Step 5: Solve for x
    x = 148,045.90/458.55
  6. Step 6: Final answer
    x = 322.86

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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.