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Finding the Fourth Proportional to 857.34, 1,285.92 and 309.36

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Solution

The fourth proportional to 857.34, 1,285.92 and 309.36 is: 464.01

Step by Step Solution

  1. Step 1: Write the proportion equation
    857.34 : 1,285.92 = 309.36 : x
  2. Step 2: Convert to fraction form
    857.34/1,285.92 = 309.36/x
  3. Step 3: Cross multiply
    857.34x = 1,285.92 × 309.36
  4. Step 4: Simplify right side
    857.34x = 397,812.21
  5. Step 5: Solve for x
    x = 397,812.21/857.34
  6. Step 6: Final answer
    x = 464.01

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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.