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Finding the Fourth Proportional to 785.37, 1,084.86 and 639.84

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Solution

The fourth proportional to 785.37, 1,084.86 and 639.84 is: 883.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    785.37 : 1,084.86 = 639.84 : x
  2. Step 2: Convert to fraction form
    785.37/1,084.86 = 639.84/x
  3. Step 3: Cross multiply
    785.37x = 1,084.86 × 639.84
  4. Step 4: Simplify right side
    785.37x = 694,136.82
  5. Step 5: Solve for x
    x = 694,136.82/785.37
  6. Step 6: Final answer
    x = 883.83

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1.5x scale

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.