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Finding the Fourth Proportional to 856.70, 1,287.94 and 676.28

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Solution

The fourth proportional to 856.70, 1,287.94 and 676.28 is: 1,016.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    856.70 : 1,287.94 = 676.28 : x
  2. Step 2: Convert to fraction form
    856.70/1,287.94 = 676.28/x
  3. Step 3: Cross multiply
    856.70x = 1,287.94 × 676.28
  4. Step 4: Simplify right side
    856.70x = 871,008.06
  5. Step 5: Solve for x
    x = 871,008.06/856.70
  6. Step 6: Final answer
    x = 1,016.70

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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.