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Finding the Fourth Proportional to 561.12, 838.45 and 428.62

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Solution

The fourth proportional to 561.12, 838.45 and 428.62 is: 640.46

Step by Step Solution

  1. Step 1: Write the proportion equation
    561.12 : 838.45 = 428.62 : x
  2. Step 2: Convert to fraction form
    561.12/838.45 = 428.62/x
  3. Step 3: Cross multiply
    561.12x = 838.45 × 428.62
  4. Step 4: Simplify right side
    561.12x = 359,376.44
  5. Step 5: Solve for x
    x = 359,376.44/561.12
  6. Step 6: Final answer
    x = 640.46

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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.