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Finding the Fourth Proportional to 319.54, 478.87 and 145.78

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Solution

The fourth proportional to 319.54, 478.87 and 145.78 is: 218.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    319.54 : 478.87 = 145.78 : x
  2. Step 2: Convert to fraction form
    319.54/478.87 = 145.78/x
  3. Step 3: Cross multiply
    319.54x = 478.87 × 145.78
  4. Step 4: Simplify right side
    319.54x = 69,808.94
  5. Step 5: Solve for x
    x = 69,808.94/319.54
  6. Step 6: Final answer
    x = 218.47

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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.