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Finding the Fourth Proportional to 318.51, 477.90 and 279.90

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Solution

The fourth proportional to 318.51, 477.90 and 279.90 is: 419.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    318.51 : 477.90 = 279.90 : x
  2. Step 2: Convert to fraction form
    318.51/477.90 = 279.90/x
  3. Step 3: Cross multiply
    318.51x = 477.90 × 279.90
  4. Step 4: Simplify right side
    318.51x = 133,764.21
  5. Step 5: Solve for x
    x = 133,764.21/318.51
  6. Step 6: Final answer
    x = 419.97

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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.