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Finding the Fourth Proportional to 278.36, 383.78 and 247.20

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Solution

The fourth proportional to 278.36, 383.78 and 247.20 is: 340.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    278.36 : 383.78 = 247.20 : x
  2. Step 2: Convert to fraction form
    278.36/383.78 = 247.20/x
  3. Step 3: Cross multiply
    278.36x = 383.78 × 247.20
  4. Step 4: Simplify right side
    278.36x = 94,869.18
  5. Step 5: Solve for x
    x = 94,869.18/278.36
  6. Step 6: Final answer
    x = 340.82

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.