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Finding the Fourth Proportional to 789.60, 1,087.38 and 641.10

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Solution

The fourth proportional to 789.60, 1,087.38 and 641.10 is: 882.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    789.60 : 1,087.38 = 641.10 : x
  2. Step 2: Convert to fraction form
    789.60/1,087.38 = 641.10/x
  3. Step 3: Cross multiply
    789.60x = 1,087.38 × 641.10
  4. Step 4: Simplify right side
    789.60x = 697,119.32
  5. Step 5: Solve for x
    x = 697,119.32/789.60
  6. Step 6: Final answer
    x = 882.88

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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.