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Finding the Fourth Proportional to 857.05, 1,285.58 and 207.79

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Solution

The fourth proportional to 857.05, 1,285.58 and 207.79 is: 311.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    857.05 : 1,285.58 = 207.79 : x
  2. Step 2: Convert to fraction form
    857.05/1,285.58 = 207.79/x
  3. Step 3: Cross multiply
    857.05x = 1,285.58 × 207.79
  4. Step 4: Simplify right side
    857.05x = 267,124.24
  5. Step 5: Solve for x
    x = 267,124.24/857.05
  6. Step 6: Final answer
    x = 311.68

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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.