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Finding the Fourth Proportional to 331.64, 497.40 and 139.28

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Solution

The fourth proportional to 331.64, 497.40 and 139.28 is: 208.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    331.64 : 497.40 = 139.28 : x
  2. Step 2: Convert to fraction form
    331.64/497.40 = 139.28/x
  3. Step 3: Cross multiply
    331.64x = 497.40 × 139.28
  4. Step 4: Simplify right side
    331.64x = 69,277.87
  5. Step 5: Solve for x
    x = 69,277.87/331.64
  6. Step 6: Final answer
    x = 208.89

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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.