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Finding the Fourth Proportional to 405.40, 606.95 and 315.15

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Solution

The fourth proportional to 405.40, 606.95 and 315.15 is: 471.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    405.40 : 606.95 = 315.15 : x
  2. Step 2: Convert to fraction form
    405.40/606.95 = 315.15/x
  3. Step 3: Cross multiply
    405.40x = 606.95 × 315.15
  4. Step 4: Simplify right side
    405.40x = 191,278.55
  5. Step 5: Solve for x
    x = 191,278.55/405.40
  6. Step 6: Final answer
    x = 471.83

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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.