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Finding the Fourth Proportional to 631.72, 872.16 and 407.85

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Solution

The fourth proportional to 631.72, 872.16 and 407.85 is: 563.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    631.72 : 872.16 = 407.85 : x
  2. Step 2: Convert to fraction form
    631.72/872.16 = 407.85/x
  3. Step 3: Cross multiply
    631.72x = 872.16 × 407.85
  4. Step 4: Simplify right side
    631.72x = 355,707.95
  5. Step 5: Solve for x
    x = 355,707.95/631.72
  6. Step 6: Final answer
    x = 563.08

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.