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Finding the Fourth Proportional to 781.44, 1,162.32 and 778.80

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Solution

The fourth proportional to 781.44, 1,162.32 and 778.80 is: 1,158.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    781.44 : 1,162.32 = 778.80 : x
  2. Step 2: Convert to fraction form
    781.44/1,162.32 = 778.80/x
  3. Step 3: Cross multiply
    781.44x = 1,162.32 × 778.80
  4. Step 4: Simplify right side
    781.44x = 905,214.82
  5. Step 5: Solve for x
    x = 905,214.82/781.44
  6. Step 6: Final answer
    x = 1,158.39

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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.