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Finding the Fourth Proportional to 431.06, 646.89 and 257.62

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Solution

The fourth proportional to 431.06, 646.89 and 257.62 is: 386.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    431.06 : 646.89 = 257.62 : x
  2. Step 2: Convert to fraction form
    431.06/646.89 = 257.62/x
  3. Step 3: Cross multiply
    431.06x = 646.89 × 257.62
  4. Step 4: Simplify right side
    431.06x = 166,648.57
  5. Step 5: Solve for x
    x = 166,648.57/431.06
  6. Step 6: Final answer
    x = 386.60

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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.