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Finding the Fourth Proportional to 770.70, 1,155.40 and 660.58

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Solution

The fourth proportional to 770.70, 1,155.40 and 660.58 is: 990.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    770.70 : 1,155.40 = 660.58 : x
  2. Step 2: Convert to fraction form
    770.70/1,155.40 = 660.58/x
  3. Step 3: Cross multiply
    770.70x = 1,155.40 × 660.58
  4. Step 4: Simplify right side
    770.70x = 763,234.13
  5. Step 5: Solve for x
    x = 763,234.13/770.70
  6. Step 6: Final answer
    x = 990.31

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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.