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Finding the Fourth Proportional to 672.38, 1,008.21 and 287.42

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Solution

The fourth proportional to 672.38, 1,008.21 and 287.42 is: 430.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    672.38 : 1,008.21 = 287.42 : x
  2. Step 2: Convert to fraction form
    672.38/1,008.21 = 287.42/x
  3. Step 3: Cross multiply
    672.38x = 1,008.21 × 287.42
  4. Step 4: Simplify right side
    672.38x = 289,779.72
  5. Step 5: Solve for x
    x = 289,779.72/672.38
  6. Step 6: Final answer
    x = 430.98

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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.