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Finding the Fourth Proportional to 1,306.29, 1,958.05 and 428.56

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Solution

The fourth proportional to 1,306.29, 1,958.05 and 428.56 is: 642.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,306.29 : 1,958.05 = 428.56 : x
  2. Step 2: Convert to fraction form
    1,306.29/1,958.05 = 428.56/x
  3. Step 3: Cross multiply
    1,306.29x = 1,958.05 × 428.56
  4. Step 4: Simplify right side
    1,306.29x = 839,137.55
  5. Step 5: Solve for x
    x = 839,137.55/1,306.29
  6. Step 6: Final answer
    x = 642.38

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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.