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Finding the Fourth Proportional to 781.16, 1,169.12 and 770.80

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Solution

The fourth proportional to 781.16, 1,169.12 and 770.80 is: 1,153.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    781.16 : 1,169.12 = 770.80 : x
  2. Step 2: Convert to fraction form
    781.16/1,169.12 = 770.80/x
  3. Step 3: Cross multiply
    781.16x = 1,169.12 × 770.80
  4. Step 4: Simplify right side
    781.16x = 901,157.70
  5. Step 5: Solve for x
    x = 901,157.70/781.16
  6. Step 6: Final answer
    x = 1,153.61

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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.