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Finding the Fourth Proportional to 1,209.96, 1,669.68 and 712.80

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Solution

The fourth proportional to 1,209.96, 1,669.68 and 712.80 is: 983.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,209.96 : 1,669.68 = 712.80 : x
  2. Step 2: Convert to fraction form
    1,209.96/1,669.68 = 712.80/x
  3. Step 3: Cross multiply
    1,209.96x = 1,669.68 × 712.80
  4. Step 4: Simplify right side
    1,209.96x = 1,190,147.90
  5. Step 5: Solve for x
    x = 1,190,147.90/1,209.96
  6. Step 6: Final answer
    x = 983.63

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.