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Finding the Fourth Proportional to 438.39, 657.65 and 145.80

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Solution

The fourth proportional to 438.39, 657.65 and 145.80 is: 218.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    438.39 : 657.65 = 145.80 : x
  2. Step 2: Convert to fraction form
    438.39/657.65 = 145.80/x
  3. Step 3: Cross multiply
    438.39x = 657.65 × 145.80
  4. Step 4: Simplify right side
    438.39x = 95,882.99
  5. Step 5: Solve for x
    x = 95,882.99/438.39
  6. Step 6: Final answer
    x = 218.72

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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.