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Finding the Fourth Proportional to 1,378.54, 2,068.11 and 647.71

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Solution

The fourth proportional to 1,378.54, 2,068.11 and 647.71 is: 971.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,378.54 : 2,068.11 = 647.71 : x
  2. Step 2: Convert to fraction form
    1,378.54/2,068.11 = 647.71/x
  3. Step 3: Cross multiply
    1,378.54x = 2,068.11 × 647.71
  4. Step 4: Simplify right side
    1,378.54x = 1,339,535.53
  5. Step 5: Solve for x
    x = 1,339,535.53/1,378.54
  6. Step 6: Final answer
    x = 971.71

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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.