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Finding the Fourth Proportional to 428.69, 643.34 and 307.06

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Solution

The fourth proportional to 428.69, 643.34 and 307.06 is: 460.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.69 : 643.34 = 307.06 : x
  2. Step 2: Convert to fraction form
    428.69/643.34 = 307.06/x
  3. Step 3: Cross multiply
    428.69x = 643.34 × 307.06
  4. Step 4: Simplify right side
    428.69x = 197,543.14
  5. Step 5: Solve for x
    x = 197,543.14/428.69
  6. Step 6: Final answer
    x = 460.80

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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.