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Finding the Fourth Proportional to 717.51, 990 and 422.79

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Solution

The fourth proportional to 717.51, 990 and 422.79 is: 583.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    717.51 : 990 = 422.79 : x
  2. Step 2: Convert to fraction form
    717.51/990 = 422.79/x
  3. Step 3: Cross multiply
    717.51x = 990 × 422.79
  4. Step 4: Simplify right side
    717.51x = 418,562.10
  5. Step 5: Solve for x
    x = 418,562.10/717.51
  6. Step 6: Final answer
    x = 583.35

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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.