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Finding the Fourth Proportional to 780.78, 1,171.17 and 757.02

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Solution

The fourth proportional to 780.78, 1,171.17 and 757.02 is: 1,135.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    780.78 : 1,171.17 = 757.02 : x
  2. Step 2: Convert to fraction form
    780.78/1,171.17 = 757.02/x
  3. Step 3: Cross multiply
    780.78x = 1,171.17 × 757.02
  4. Step 4: Simplify right side
    780.78x = 886,599.11
  5. Step 5: Solve for x
    x = 886,599.11/780.78
  6. Step 6: Final answer
    x = 1,135.53

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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.