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Finding the Fourth Proportional to 857.22, 1,285.91 and 309.36

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Solution

The fourth proportional to 857.22, 1,285.91 and 309.36 is: 464.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    857.22 : 1,285.91 = 309.36 : x
  2. Step 2: Convert to fraction form
    857.22/1,285.91 = 309.36/x
  3. Step 3: Cross multiply
    857.22x = 1,285.91 × 309.36
  4. Step 4: Simplify right side
    857.22x = 397,809.12
  5. Step 5: Solve for x
    x = 397,809.12/857.22
  6. Step 6: Final answer
    x = 464.07

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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.