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Finding the Fourth Proportional to 717.86, 990.40 and 419.03

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Solution

The fourth proportional to 717.86, 990.40 and 419.03 is: 578.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    717.86 : 990.40 = 419.03 : x
  2. Step 2: Convert to fraction form
    717.86/990.40 = 419.03/x
  3. Step 3: Cross multiply
    717.86x = 990.40 × 419.03
  4. Step 4: Simplify right side
    717.86x = 415,007.31
  5. Step 5: Solve for x
    x = 415,007.31/717.86
  6. Step 6: Final answer
    x = 578.12

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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.