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Finding the Fourth Proportional to 856.64, 1,286.70 and 756.20

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Solution

The fourth proportional to 856.64, 1,286.70 and 756.20 is: 1,135.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    856.64 : 1,286.70 = 756.20 : x
  2. Step 2: Convert to fraction form
    856.64/1,286.70 = 756.20/x
  3. Step 3: Cross multiply
    856.64x = 1,286.70 × 756.20
  4. Step 4: Simplify right side
    856.64x = 973,002.54
  5. Step 5: Solve for x
    x = 973,002.54/856.64
  6. Step 6: Final answer
    x = 1,135.84

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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.