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Finding the Fourth Proportional to 486.90, 671.87 and 290.38

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Solution

The fourth proportional to 486.90, 671.87 and 290.38 is: 400.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    486.90 : 671.87 = 290.38 : x
  2. Step 2: Convert to fraction form
    486.90/671.87 = 290.38/x
  3. Step 3: Cross multiply
    486.90x = 671.87 × 290.38
  4. Step 4: Simplify right side
    486.90x = 195,094.48
  5. Step 5: Solve for x
    x = 195,094.48/486.90
  6. Step 6: Final answer
    x = 400.69

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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.