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Finding the Fourth Proportional to 405.12, 607.08 and 212.28

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Solution

The fourth proportional to 405.12, 607.08 and 212.28 is: 318.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    405.12 : 607.08 = 212.28 : x
  2. Step 2: Convert to fraction form
    405.12/607.08 = 212.28/x
  3. Step 3: Cross multiply
    405.12x = 607.08 × 212.28
  4. Step 4: Simplify right side
    405.12x = 128,870.94
  5. Step 5: Solve for x
    x = 128,870.94/405.12
  6. Step 6: Final answer
    x = 318.11

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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.