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Finding the Fourth Proportional to 431.29, 646.55 and 208.81

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Solution

The fourth proportional to 431.29, 646.55 and 208.81 is: 313.03

Step by Step Solution

  1. Step 1: Write the proportion equation
    431.29 : 646.55 = 208.81 : x
  2. Step 2: Convert to fraction form
    431.29/646.55 = 208.81/x
  3. Step 3: Cross multiply
    431.29x = 646.55 × 208.81
  4. Step 4: Simplify right side
    431.29x = 135,006.11
  5. Step 5: Solve for x
    x = 135,006.11/431.29
  6. Step 6: Final answer
    x = 313.03

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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.