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Finding the Fourth Proportional to 1,288.35, 1,778.40 and 817.07

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Solution

The fourth proportional to 1,288.35, 1,778.40 and 817.07 is: 1,127.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,288.35 : 1,778.40 = 817.07 : x
  2. Step 2: Convert to fraction form
    1,288.35/1,778.40 = 817.07/x
  3. Step 3: Cross multiply
    1,288.35x = 1,778.40 × 817.07
  4. Step 4: Simplify right side
    1,288.35x = 1,453,068.40
  5. Step 5: Solve for x
    x = 1,453,068.40/1,288.35
  6. Step 6: Final answer
    x = 1,127.85

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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.