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Finding the Fourth Proportional to 431.04, 646.73 and 257.81

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Solution

The fourth proportional to 431.04, 646.73 and 257.81 is: 386.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    431.04 : 646.73 = 257.81 : x
  2. Step 2: Convert to fraction form
    431.04/646.73 = 257.81/x
  3. Step 3: Cross multiply
    431.04x = 646.73 × 257.81
  4. Step 4: Simplify right side
    431.04x = 166,728.94
  5. Step 5: Solve for x
    x = 166,728.94/431.04
  6. Step 6: Final answer
    x = 386.81

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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.