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Finding the Fourth Proportional to 478.78, 719.45 and 259.55

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Solution

The fourth proportional to 478.78, 719.45 and 259.55 is: 390.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    478.78 : 719.45 = 259.55 : x
  2. Step 2: Convert to fraction form
    478.78/719.45 = 259.55/x
  3. Step 3: Cross multiply
    478.78x = 719.45 × 259.55
  4. Step 4: Simplify right side
    478.78x = 186,729.65
  5. Step 5: Solve for x
    x = 186,729.65/478.78
  6. Step 6: Final answer
    x = 390.02

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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.