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Finding the Fourth Proportional to 678.49, 1,017.86 and 288.49

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Solution

The fourth proportional to 678.49, 1,017.86 and 288.49 is: 432.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    678.49 : 1,017.86 = 288.49 : x
  2. Step 2: Convert to fraction form
    678.49/1,017.86 = 288.49/x
  3. Step 3: Cross multiply
    678.49x = 1,017.86 × 288.49
  4. Step 4: Simplify right side
    678.49x = 293,640.61
  5. Step 5: Solve for x
    x = 293,640.61/678.49
  6. Step 6: Final answer
    x = 432.79

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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.