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Finding the Fourth Proportional to 430, 645 and 378.64

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Solution

The fourth proportional to 430, 645 and 378.64 is: 567.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    430 : 645 = 378.64 : x
  2. Step 2: Convert to fraction form
    430/645 = 378.64/x
  3. Step 3: Cross multiply
    430x = 645 × 378.64
  4. Step 4: Simplify right side
    430x = 244,222.80
  5. Step 5: Solve for x
    x = 244,222.80/430
  6. Step 6: Final answer
    x = 567.96

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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.