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Finding the Fourth Proportional to 861.32, 1,296.67 and 784.78

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Solution

The fourth proportional to 861.32, 1,296.67 and 784.78 is: 1,181.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    861.32 : 1,296.67 = 784.78 : x
  2. Step 2: Convert to fraction form
    861.32/1,296.67 = 784.78/x
  3. Step 3: Cross multiply
    861.32x = 1,296.67 × 784.78
  4. Step 4: Simplify right side
    861.32x = 1,017,594.20
  5. Step 5: Solve for x
    x = 1,017,594.20/861.32
  6. Step 6: Final answer
    x = 1,181.44

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.