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Finding the Fourth Proportional to 678.26, 1,015.57 and 434.05

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Solution

The fourth proportional to 678.26, 1,015.57 and 434.05 is: 649.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    678.26 : 1,015.57 = 434.05 : x
  2. Step 2: Convert to fraction form
    678.26/1,015.57 = 434.05/x
  3. Step 3: Cross multiply
    678.26x = 1,015.57 × 434.05
  4. Step 4: Simplify right side
    678.26x = 440,806.16
  5. Step 5: Solve for x
    x = 440,806.16/678.26
  6. Step 6: Final answer
    x = 649.90

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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.