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Finding the Fourth Proportional to 355, 489.54 and 289.30

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Solution

The fourth proportional to 355, 489.54 and 289.30 is: 398.94

Step by Step Solution

  1. Step 1: Write the proportion equation
    355 : 489.54 = 289.30 : x
  2. Step 2: Convert to fraction form
    355/489.54 = 289.30/x
  3. Step 3: Cross multiply
    355x = 489.54 × 289.30
  4. Step 4: Simplify right side
    355x = 141,623.92
  5. Step 5: Solve for x
    x = 141,623.92/355
  6. Step 6: Final answer
    x = 398.94

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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.