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Finding the Fourth Proportional to 858.31, 1,288.20 and 338.68

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Solution

The fourth proportional to 858.31, 1,288.20 and 338.68 is: 508.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    858.31 : 1,288.20 = 338.68 : x
  2. Step 2: Convert to fraction form
    858.31/1,288.20 = 338.68/x
  3. Step 3: Cross multiply
    858.31x = 1,288.20 × 338.68
  4. Step 4: Simplify right side
    858.31x = 436,287.58
  5. Step 5: Solve for x
    x = 436,287.58/858.31
  6. Step 6: Final answer
    x = 508.31

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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.