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Finding the Fourth Proportional to 407.50, 611.80 and 378.80

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Solution

The fourth proportional to 407.50, 611.80 and 378.80 is: 568.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    407.50 : 611.80 = 378.80 : x
  2. Step 2: Convert to fraction form
    407.50/611.80 = 378.80/x
  3. Step 3: Cross multiply
    407.50x = 611.80 × 378.80
  4. Step 4: Simplify right side
    407.50x = 231,749.84
  5. Step 5: Solve for x
    x = 231,749.84/407.50
  6. Step 6: Final answer
    x = 568.71

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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.