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Finding the Fourth Proportional to 842.40, 1,261.19 and 669.31

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Solution

The fourth proportional to 842.40, 1,261.19 and 669.31 is: 1,002.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    842.40 : 1,261.19 = 669.31 : x
  2. Step 2: Convert to fraction form
    842.40/1,261.19 = 669.31/x
  3. Step 3: Cross multiply
    842.40x = 1,261.19 × 669.31
  4. Step 4: Simplify right side
    842.40x = 844,125.60
  5. Step 5: Solve for x
    x = 844,125.60/842.40
  6. Step 6: Final answer
    x = 1,002.05

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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.