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Finding the Fourth Proportional to 319.53, 478.08 and 258.78

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Solution

The fourth proportional to 319.53, 478.08 and 258.78 is: 387.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    319.53 : 478.08 = 258.78 : x
  2. Step 2: Convert to fraction form
    319.53/478.08 = 258.78/x
  3. Step 3: Cross multiply
    319.53x = 478.08 × 258.78
  4. Step 4: Simplify right side
    319.53x = 123,717.54
  5. Step 5: Solve for x
    x = 123,717.54/319.53
  6. Step 6: Final answer
    x = 387.19

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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.