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Finding the Fourth Proportional to 285.29, 427.95 and 79.85

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Solution

The fourth proportional to 285.29, 427.95 and 79.85 is: 119.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    285.29 : 427.95 = 79.85 : x
  2. Step 2: Convert to fraction form
    285.29/427.95 = 79.85/x
  3. Step 3: Cross multiply
    285.29x = 427.95 × 79.85
  4. Step 4: Simplify right side
    285.29x = 34,172.88
  5. Step 5: Solve for x
    x = 34,172.88/285.29
  6. Step 6: Final answer
    x = 119.78

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.