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Finding the Fourth Proportional to 315.92, 435.76 and 289.78

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Solution

The fourth proportional to 315.92, 435.76 and 289.78 is: 399.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    315.92 : 435.76 = 289.78 : x
  2. Step 2: Convert to fraction form
    315.92/435.76 = 289.78/x
  3. Step 3: Cross multiply
    315.92x = 435.76 × 289.78
  4. Step 4: Simplify right side
    315.92x = 126,273.94
  5. Step 5: Solve for x
    x = 126,273.94/315.92
  6. Step 6: Final answer
    x = 399.70

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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.