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Finding the Fourth Proportional to 721.98, 987.80 and 718.92

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Solution

The fourth proportional to 721.98, 987.80 and 718.92 is: 983.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    721.98 : 987.80 = 718.92 : x
  2. Step 2: Convert to fraction form
    721.98/987.80 = 718.92/x
  3. Step 3: Cross multiply
    721.98x = 987.80 × 718.92
  4. Step 4: Simplify right side
    721.98x = 710,145.58
  5. Step 5: Solve for x
    x = 710,145.58/721.98
  6. Step 6: Final answer
    x = 983.61

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.