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Finding the Fourth Proportional to 1,138.96, 1,571.79 and 641.58

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Solution

The fourth proportional to 1,138.96, 1,571.79 and 641.58 is: 885.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,138.96 : 1,571.79 = 641.58 : x
  2. Step 2: Convert to fraction form
    1,138.96/1,571.79 = 641.58/x
  3. Step 3: Cross multiply
    1,138.96x = 1,571.79 × 641.58
  4. Step 4: Simplify right side
    1,138.96x = 1,008,429.03
  5. Step 5: Solve for x
    x = 1,008,429.03/1,138.96
  6. Step 6: Final answer
    x = 885.39

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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.