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Finding the Fourth Proportional to 717.98, 990.64 and 419.05

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Solution

The fourth proportional to 717.98, 990.64 and 419.05 is: 578.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    717.98 : 990.64 = 419.05 : x
  2. Step 2: Convert to fraction form
    717.98/990.64 = 419.05/x
  3. Step 3: Cross multiply
    717.98x = 990.64 × 419.05
  4. Step 4: Simplify right side
    717.98x = 415,127.69
  5. Step 5: Solve for x
    x = 415,127.69/717.98
  6. Step 6: Final answer
    x = 578.19

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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.