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Finding the Fourth Proportional to 780.78, 1,169.76 and 455.46

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Solution

The fourth proportional to 780.78, 1,169.76 and 455.46 is: 682.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    780.78 : 1,169.76 = 455.46 : x
  2. Step 2: Convert to fraction form
    780.78/1,169.76 = 455.46/x
  3. Step 3: Cross multiply
    780.78x = 1,169.76 × 455.46
  4. Step 4: Simplify right side
    780.78x = 532,778.89
  5. Step 5: Solve for x
    x = 532,778.89/780.78
  6. Step 6: Final answer
    x = 682.37

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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.