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Finding the Fourth Proportional to 665.52, 991.38 and 656.88

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Solution

The fourth proportional to 665.52, 991.38 and 656.88 is: 978.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    665.52 : 991.38 = 656.88 : x
  2. Step 2: Convert to fraction form
    665.52/991.38 = 656.88/x
  3. Step 3: Cross multiply
    665.52x = 991.38 × 656.88
  4. Step 4: Simplify right side
    665.52x = 651,217.69
  5. Step 5: Solve for x
    x = 651,217.69/665.52
  6. Step 6: Final answer
    x = 978.51

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.