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Finding the Fourth Proportional to 805.61, 1,112.99 and 688.79

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Solution

The fourth proportional to 805.61, 1,112.99 and 688.79 is: 951.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    805.61 : 1,112.99 = 688.79 : x
  2. Step 2: Convert to fraction form
    805.61/1,112.99 = 688.79/x
  3. Step 3: Cross multiply
    805.61x = 1,112.99 × 688.79
  4. Step 4: Simplify right side
    805.61x = 766,615.72
  5. Step 5: Solve for x
    x = 766,615.72/805.61
  6. Step 6: Final answer
    x = 951.59

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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.