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Finding the Fourth Proportional to 699.42, 1,047.69 and 690.78

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Solution

The fourth proportional to 699.42, 1,047.69 and 690.78 is: 1,034.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    699.42 : 1,047.69 = 690.78 : x
  2. Step 2: Convert to fraction form
    699.42/1,047.69 = 690.78/x
  3. Step 3: Cross multiply
    699.42x = 1,047.69 × 690.78
  4. Step 4: Simplify right side
    699.42x = 723,723.30
  5. Step 5: Solve for x
    x = 723,723.30/699.42
  6. Step 6: Final answer
    x = 1,034.75

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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.