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Finding the Fourth Proportional to 720.64, 987.04 and 680.80

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Solution

The fourth proportional to 720.64, 987.04 and 680.80 is: 932.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    720.64 : 987.04 = 680.80 : x
  2. Step 2: Convert to fraction form
    720.64/987.04 = 680.80/x
  3. Step 3: Cross multiply
    720.64x = 987.04 × 680.80
  4. Step 4: Simplify right side
    720.64x = 671,976.83
  5. Step 5: Solve for x
    x = 671,976.83/720.64
  6. Step 6: Final answer
    x = 932.47

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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.