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Finding the Fourth Proportional to 644.28, 965.55 and 278.55

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Solution

The fourth proportional to 644.28, 965.55 and 278.55 is: 417.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    644.28 : 965.55 = 278.55 : x
  2. Step 2: Convert to fraction form
    644.28/965.55 = 278.55/x
  3. Step 3: Cross multiply
    644.28x = 965.55 × 278.55
  4. Step 4: Simplify right side
    644.28x = 268,953.95
  5. Step 5: Solve for x
    x = 268,953.95/644.28
  6. Step 6: Final answer
    x = 417.45

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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.