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Finding the Fourth Proportional to 458.66, 687.78 and 215.25

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Solution

The fourth proportional to 458.66, 687.78 and 215.25 is: 322.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    458.66 : 687.78 = 215.25 : x
  2. Step 2: Convert to fraction form
    458.66/687.78 = 215.25/x
  3. Step 3: Cross multiply
    458.66x = 687.78 × 215.25
  4. Step 4: Simplify right side
    458.66x = 148,044.65
  5. Step 5: Solve for x
    x = 148,044.65/458.66
  6. Step 6: Final answer
    x = 322.78

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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.