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Finding the Fourth Proportional to 711.05, 1,065.90 and 638.15

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Solution

The fourth proportional to 711.05, 1,065.90 and 638.15 is: 956.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    711.05 : 1,065.90 = 638.15 : x
  2. Step 2: Convert to fraction form
    711.05/1,065.90 = 638.15/x
  3. Step 3: Cross multiply
    711.05x = 1,065.90 × 638.15
  4. Step 4: Simplify right side
    711.05x = 680,204.09
  5. Step 5: Solve for x
    x = 680,204.09/711.05
  6. Step 6: Final answer
    x = 956.62

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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.