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Finding the Fourth Proportional to 688.55, 1,034.62 and 643.56

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Solution

The fourth proportional to 688.55, 1,034.62 and 643.56 is: 967.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    688.55 : 1,034.62 = 643.56 : x
  2. Step 2: Convert to fraction form
    688.55/1,034.62 = 643.56/x
  3. Step 3: Cross multiply
    688.55x = 1,034.62 × 643.56
  4. Step 4: Simplify right side
    688.55x = 665,841.66
  5. Step 5: Solve for x
    x = 665,841.66/688.55
  6. Step 6: Final answer
    x = 967.02

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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.