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Finding the Fourth Proportional to 421.70, 631.57 and 407.10

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Solution

The fourth proportional to 421.70, 631.57 and 407.10 is: 609.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.70 : 631.57 = 407.10 : x
  2. Step 2: Convert to fraction form
    421.70/631.57 = 407.10/x
  3. Step 3: Cross multiply
    421.70x = 631.57 × 407.10
  4. Step 4: Simplify right side
    421.70x = 257,112.66
  5. Step 5: Solve for x
    x = 257,112.66/421.70
  6. Step 6: Final answer
    x = 609.71

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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.