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Finding the Fourth Proportional to 628.80, 942.78 and 385.53

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Solution

The fourth proportional to 628.80, 942.78 and 385.53 is: 578.04

Step by Step Solution

  1. Step 1: Write the proportion equation
    628.80 : 942.78 = 385.53 : x
  2. Step 2: Convert to fraction form
    628.80/942.78 = 385.53/x
  3. Step 3: Cross multiply
    628.80x = 942.78 × 385.53
  4. Step 4: Simplify right side
    628.80x = 363,469.97
  5. Step 5: Solve for x
    x = 363,469.97/628.80
  6. Step 6: Final answer
    x = 578.04

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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.