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Finding the Fourth Proportional to 856.67, 1,284.97 and 309.20

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Solution

The fourth proportional to 856.67, 1,284.97 and 309.20 is: 463.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    856.67 : 1,284.97 = 309.20 : x
  2. Step 2: Convert to fraction form
    856.67/1,284.97 = 309.20/x
  3. Step 3: Cross multiply
    856.67x = 1,284.97 × 309.20
  4. Step 4: Simplify right side
    856.67x = 397,311.18
  5. Step 5: Solve for x
    x = 397,311.18/856.67
  6. Step 6: Final answer
    x = 463.79

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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.