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Finding the Fourth Proportional to 290.90, 397.88 and 286.58

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Solution

The fourth proportional to 290.90, 397.88 and 286.58 is: 391.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    290.90 : 397.88 = 286.58 : x
  2. Step 2: Convert to fraction form
    290.90/397.88 = 286.58/x
  3. Step 3: Cross multiply
    290.90x = 397.88 × 286.58
  4. Step 4: Simplify right side
    290.90x = 114,024.45
  5. Step 5: Solve for x
    x = 114,024.45/290.90
  6. Step 6: Final answer
    x = 391.97

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.