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Finding the Fourth Proportional to 717.21, 989.80 and 402.50

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Solution

The fourth proportional to 717.21, 989.80 and 402.50 is: 555.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    717.21 : 989.80 = 402.50 : x
  2. Step 2: Convert to fraction form
    717.21/989.80 = 402.50/x
  3. Step 3: Cross multiply
    717.21x = 989.80 × 402.50
  4. Step 4: Simplify right side
    717.21x = 398,398.58
  5. Step 5: Solve for x
    x = 398,398.58/717.21
  6. Step 6: Final answer
    x = 555.48

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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.