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Finding the Fourth Proportional to 421.75, 631.51 and 339.08

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Solution

The fourth proportional to 421.75, 631.51 and 339.08 is: 507.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.75 : 631.51 = 339.08 : x
  2. Step 2: Convert to fraction form
    421.75/631.51 = 339.08/x
  3. Step 3: Cross multiply
    421.75x = 631.51 × 339.08
  4. Step 4: Simplify right side
    421.75x = 214,132.41
  5. Step 5: Solve for x
    x = 214,132.41/421.75
  6. Step 6: Final answer
    x = 507.72

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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.