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Finding the Fourth Proportional to 778.34, 1,166.60 and 639.84

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Solution

The fourth proportional to 778.34, 1,166.60 and 639.84 is: 959.01

Step by Step Solution

  1. Step 1: Write the proportion equation
    778.34 : 1,166.60 = 639.84 : x
  2. Step 2: Convert to fraction form
    778.34/1,166.60 = 639.84/x
  3. Step 3: Cross multiply
    778.34x = 1,166.60 × 639.84
  4. Step 4: Simplify right side
    778.34x = 746,437.34
  5. Step 5: Solve for x
    x = 746,437.34/778.34
  6. Step 6: Final answer
    x = 959.01

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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.