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Finding the Fourth Proportional to 720.54, 1,078.32 and 699.78

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Solution

The fourth proportional to 720.54, 1,078.32 and 699.78 is: 1,047.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    720.54 : 1,078.32 = 699.78 : x
  2. Step 2: Convert to fraction form
    720.54/1,078.32 = 699.78/x
  3. Step 3: Cross multiply
    720.54x = 1,078.32 × 699.78
  4. Step 4: Simplify right side
    720.54x = 754,586.77
  5. Step 5: Solve for x
    x = 754,586.77/720.54
  6. Step 6: Final answer
    x = 1,047.25

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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.