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Finding the Fourth Proportional to 421.95, 632.06 and 391.20

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Solution

The fourth proportional to 421.95, 632.06 and 391.20 is: 585.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.95 : 632.06 = 391.20 : x
  2. Step 2: Convert to fraction form
    421.95/632.06 = 391.20/x
  3. Step 3: Cross multiply
    421.95x = 632.06 × 391.20
  4. Step 4: Simplify right side
    421.95x = 247,257.24
  5. Step 5: Solve for x
    x = 247,257.24/421.95
  6. Step 6: Final answer
    x = 585.98

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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.