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Finding the Fourth Proportional to 289.90, 396.51 and 285.58

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Solution

The fourth proportional to 289.90, 396.51 and 285.58 is: 390.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    289.90 : 396.51 = 285.58 : x
  2. Step 2: Convert to fraction form
    289.90/396.51 = 285.58/x
  3. Step 3: Cross multiply
    289.90x = 396.51 × 285.58
  4. Step 4: Simplify right side
    289.90x = 113,235.33
  5. Step 5: Solve for x
    x = 113,235.33/289.90
  6. Step 6: Final answer
    x = 390.60

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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.