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Finding the Fourth Proportional to 842.80, 1,264.31 and 287.60

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Solution

The fourth proportional to 842.80, 1,264.31 and 287.60 is: 431.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    842.80 : 1,264.31 = 287.60 : x
  2. Step 2: Convert to fraction form
    842.80/1,264.31 = 287.60/x
  3. Step 3: Cross multiply
    842.80x = 1,264.31 × 287.60
  4. Step 4: Simplify right side
    842.80x = 363,615.56
  5. Step 5: Solve for x
    x = 363,615.56/842.80
  6. Step 6: Final answer
    x = 431.44

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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.