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Finding the Fourth Proportional to 405.68, 607.92 and 212.72

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Solution

The fourth proportional to 405.68, 607.92 and 212.72 is: 318.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    405.68 : 607.92 = 212.72 : x
  2. Step 2: Convert to fraction form
    405.68/607.92 = 212.72/x
  3. Step 3: Cross multiply
    405.68x = 607.92 × 212.72
  4. Step 4: Simplify right side
    405.68x = 129,316.74
  5. Step 5: Solve for x
    x = 129,316.74/405.68
  6. Step 6: Final answer
    x = 318.77

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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.