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Finding the Fourth Proportional to 1,317.83, 1,818.54 and 786.78

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Solution

The fourth proportional to 1,317.83, 1,818.54 and 786.78 is: 1,085.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,317.83 : 1,818.54 = 786.78 : x
  2. Step 2: Convert to fraction form
    1,317.83/1,818.54 = 786.78/x
  3. Step 3: Cross multiply
    1,317.83x = 1,818.54 × 786.78
  4. Step 4: Simplify right side
    1,317.83x = 1,430,790.90
  5. Step 5: Solve for x
    x = 1,430,790.90/1,317.83
  6. Step 6: Final answer
    x = 1,085.72

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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.