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Finding the Fourth Proportional to 721.65, 995.86 and 406.91

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Solution

The fourth proportional to 721.65, 995.86 and 406.91 is: 561.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    721.65 : 995.86 = 406.91 : x
  2. Step 2: Convert to fraction form
    721.65/995.86 = 406.91/x
  3. Step 3: Cross multiply
    721.65x = 995.86 × 406.91
  4. Step 4: Simplify right side
    721.65x = 405,225.27
  5. Step 5: Solve for x
    x = 405,225.27/721.65
  6. Step 6: Final answer
    x = 561.53

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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.