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Finding the Fourth Proportional to 661.48, 991.31 and 531.78

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Solution

The fourth proportional to 661.48, 991.31 and 531.78 is: 796.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.48 : 991.31 = 531.78 : x
  2. Step 2: Convert to fraction form
    661.48/991.31 = 531.78/x
  3. Step 3: Cross multiply
    661.48x = 991.31 × 531.78
  4. Step 4: Simplify right side
    661.48x = 527,152.46
  5. Step 5: Solve for x
    x = 527,152.46/661.48
  6. Step 6: Final answer
    x = 796.93

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.