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Finding the Fourth Proportional to 709.91, 980 and 665.63

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Solution

The fourth proportional to 709.91, 980 and 665.63 is: 918.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    709.91 : 980 = 665.63 : x
  2. Step 2: Convert to fraction form
    709.91/980 = 665.63/x
  3. Step 3: Cross multiply
    709.91x = 980 × 665.63
  4. Step 4: Simplify right side
    709.91x = 652,317.40
  5. Step 5: Solve for x
    x = 652,317.40/709.91
  6. Step 6: Final answer
    x = 918.87

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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.