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Finding the Fourth Proportional to 783.20, 1,082.92 and 770.80

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Solution

The fourth proportional to 783.20, 1,082.92 and 770.80 is: 1,065.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    783.20 : 1,082.92 = 770.80 : x
  2. Step 2: Convert to fraction form
    783.20/1,082.92 = 770.80/x
  3. Step 3: Cross multiply
    783.20x = 1,082.92 × 770.80
  4. Step 4: Simplify right side
    783.20x = 834,714.74
  5. Step 5: Solve for x
    x = 834,714.74/783.20
  6. Step 6: Final answer
    x = 1,065.77

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.