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Finding the Fourth Proportional to 678.53, 1,019.15 and 659.39

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Solution

The fourth proportional to 678.53, 1,019.15 and 659.39 is: 990.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    678.53 : 1,019.15 = 659.39 : x
  2. Step 2: Convert to fraction form
    678.53/1,019.15 = 659.39/x
  3. Step 3: Cross multiply
    678.53x = 1,019.15 × 659.39
  4. Step 4: Simplify right side
    678.53x = 672,013.87
  5. Step 5: Solve for x
    x = 672,013.87/678.53
  6. Step 6: Final answer
    x = 990.40

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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.