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Finding the Fourth Proportional to 389.61, 535.95 and 315.77

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Solution

The fourth proportional to 389.61, 535.95 and 315.77 is: 434.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    389.61 : 535.95 = 315.77 : x
  2. Step 2: Convert to fraction form
    389.61/535.95 = 315.77/x
  3. Step 3: Cross multiply
    389.61x = 535.95 × 315.77
  4. Step 4: Simplify right side
    389.61x = 169,234.25
  5. Step 5: Solve for x
    x = 169,234.25/389.61
  6. Step 6: Final answer
    x = 434.37

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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.