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Finding the Fourth Proportional to 659.90, 910.80 and 398.06

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Solution

The fourth proportional to 659.90, 910.80 and 398.06 is: 549.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    659.90 : 910.80 = 398.06 : x
  2. Step 2: Convert to fraction form
    659.90/910.80 = 398.06/x
  3. Step 3: Cross multiply
    659.90x = 910.80 × 398.06
  4. Step 4: Simplify right side
    659.90x = 362,553.05
  5. Step 5: Solve for x
    x = 362,553.05/659.90
  6. Step 6: Final answer
    x = 549.41

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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.