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Finding the Fourth Proportional to 290.59, 398.42 and 285.40

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Solution

The fourth proportional to 290.59, 398.42 and 285.40 is: 391.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    290.59 : 398.42 = 285.40 : x
  2. Step 2: Convert to fraction form
    290.59/398.42 = 285.40/x
  3. Step 3: Cross multiply
    290.59x = 398.42 × 285.40
  4. Step 4: Simplify right side
    290.59x = 113,706.36
  5. Step 5: Solve for x
    x = 113,706.36/290.59
  6. Step 6: Final answer
    x = 391.29

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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.