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Finding the Fourth Proportional to 857.06, 1,285.70 and 309.17

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Solution

The fourth proportional to 857.06, 1,285.70 and 309.17 is: 463.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    857.06 : 1,285.70 = 309.17 : x
  2. Step 2: Convert to fraction form
    857.06/1,285.70 = 309.17/x
  3. Step 3: Cross multiply
    857.06x = 1,285.70 × 309.17
  4. Step 4: Simplify right side
    857.06x = 397,495.17
  5. Step 5: Solve for x
    x = 397,495.17/857.06
  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.