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Finding the Fourth Proportional to 438.40, 651.11 and 430.30

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Solution

The fourth proportional to 438.40, 651.11 and 430.30 is: 639.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    438.40 : 651.11 = 430.30 : x
  2. Step 2: Convert to fraction form
    438.40/651.11 = 430.30/x
  3. Step 3: Cross multiply
    438.40x = 651.11 × 430.30
  4. Step 4: Simplify right side
    438.40x = 280,172.63
  5. Step 5: Solve for x
    x = 280,172.63/438.40
  6. Step 6: Final answer
    x = 639.08

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.