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Finding the Fourth Proportional to 678.85, 1,018.45 and 288.86

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Solution

The fourth proportional to 678.85, 1,018.45 and 288.86 is: 433.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    678.85 : 1,018.45 = 288.86 : x
  2. Step 2: Convert to fraction form
    678.85/1,018.45 = 288.86/x
  3. Step 3: Cross multiply
    678.85x = 1,018.45 × 288.86
  4. Step 4: Simplify right side
    678.85x = 294,188.02
  5. Step 5: Solve for x
    x = 294,188.02/678.85
  6. Step 6: Final answer
    x = 433.37

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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.