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Finding the Fourth Proportional to 1,239.66, 1,861.02 and 771.82

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Solution

The fourth proportional to 1,239.66, 1,861.02 and 771.82 is: 1,158.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,239.66 : 1,861.02 = 771.82 : x
  2. Step 2: Convert to fraction form
    1,239.66/1,861.02 = 771.82/x
  3. Step 3: Cross multiply
    1,239.66x = 1,861.02 × 771.82
  4. Step 4: Simplify right side
    1,239.66x = 1,436,372.46
  5. Step 5: Solve for x
    x = 1,436,372.46/1,239.66
  6. Step 6: Final answer
    x = 1,158.68

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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.