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Finding the Fourth Proportional to 785.91, 1,084.13 and 638.28

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Solution

The fourth proportional to 785.91, 1,084.13 and 638.28 is: 880.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    785.91 : 1,084.13 = 638.28 : x
  2. Step 2: Convert to fraction form
    785.91/1,084.13 = 638.28/x
  3. Step 3: Cross multiply
    785.91x = 1,084.13 × 638.28
  4. Step 4: Simplify right side
    785.91x = 691,978.50
  5. Step 5: Solve for x
    x = 691,978.50/785.91
  6. Step 6: Final answer
    x = 880.48

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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.