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Finding the Fourth Proportional to 691.09, 1,036.41 and 280.42

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Solution

The fourth proportional to 691.09, 1,036.41 and 280.42 is: 420.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    691.09 : 1,036.41 = 280.42 : x
  2. Step 2: Convert to fraction form
    691.09/1,036.41 = 280.42/x
  3. Step 3: Cross multiply
    691.09x = 1,036.41 × 280.42
  4. Step 4: Simplify right side
    691.09x = 290,630.09
  5. Step 5: Solve for x
    x = 290,630.09/691.09
  6. Step 6: Final answer
    x = 420.54

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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.