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Finding the Fourth Proportional to 385.61, 531.70 and 306.77

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Solution

The fourth proportional to 385.61, 531.70 and 306.77 is: 422.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    385.61 : 531.70 = 306.77 : x
  2. Step 2: Convert to fraction form
    385.61/531.70 = 306.77/x
  3. Step 3: Cross multiply
    385.61x = 531.70 × 306.77
  4. Step 4: Simplify right side
    385.61x = 163,106.18
  5. Step 5: Solve for x
    x = 163,106.18/385.61
  6. Step 6: Final answer
    x = 422.99

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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.