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Finding the Fourth Proportional to 405, 607.91 and 212.63

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Solution

The fourth proportional to 405, 607.91 and 212.63 is: 319.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    405 : 607.91 = 212.63 : x
  2. Step 2: Convert to fraction form
    405/607.91 = 212.63/x
  3. Step 3: Cross multiply
    405x = 607.91 × 212.63
  4. Step 4: Simplify right side
    405x = 129,255.80
  5. Step 5: Solve for x
    x = 129,255.80/405
  6. Step 6: Final answer
    x = 319.15

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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.