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Finding the Fourth Proportional to 422.40, 637.42 and 407.15

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Solution

The fourth proportional to 422.40, 637.42 and 407.15 is: 614.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    422.40 : 637.42 = 407.15 : x
  2. Step 2: Convert to fraction form
    422.40/637.42 = 407.15/x
  3. Step 3: Cross multiply
    422.40x = 637.42 × 407.15
  4. Step 4: Simplify right side
    422.40x = 259,525.55
  5. Step 5: Solve for x
    x = 259,525.55/422.40
  6. Step 6: Final answer
    x = 614.41

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.