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Finding the Fourth Proportional to 431.63, 647.60 and 215.16

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Solution

The fourth proportional to 431.63, 647.60 and 215.16 is: 322.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    431.63 : 647.60 = 215.16 : x
  2. Step 2: Convert to fraction form
    431.63/647.60 = 215.16/x
  3. Step 3: Cross multiply
    431.63x = 647.60 × 215.16
  4. Step 4: Simplify right side
    431.63x = 139,334.11
  5. Step 5: Solve for x
    x = 139,334.11/431.63
  6. Step 6: Final answer
    x = 322.81

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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.