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Finding the Fourth Proportional to 716.80, 989.19 and 402.09

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Solution

The fourth proportional to 716.80, 989.19 and 402.09 is: 554.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    716.80 : 989.19 = 402.09 : x
  2. Step 2: Convert to fraction form
    716.80/989.19 = 402.09/x
  3. Step 3: Cross multiply
    716.80x = 989.19 × 402.09
  4. Step 4: Simplify right side
    716.80x = 397,743.41
  5. Step 5: Solve for x
    x = 397,743.41/716.80
  6. Step 6: Final answer
    x = 554.89

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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.