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Finding the Fourth Proportional to 719.21, 990.43 and 497.79

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Solution

The fourth proportional to 719.21, 990.43 and 497.79 is: 685.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    719.21 : 990.43 = 497.79 : x
  2. Step 2: Convert to fraction form
    719.21/990.43 = 497.79/x
  3. Step 3: Cross multiply
    719.21x = 990.43 × 497.79
  4. Step 4: Simplify right side
    719.21x = 493,024.91
  5. Step 5: Solve for x
    x = 493,024.91/719.21
  6. Step 6: Final answer
    x = 685.51

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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.