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Finding the Fourth Proportional to 289.09, 431.06 and 278.56

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Solution

The fourth proportional to 289.09, 431.06 and 278.56 is: 415.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    289.09 : 431.06 = 278.56 : x
  2. Step 2: Convert to fraction form
    289.09/431.06 = 278.56/x
  3. Step 3: Cross multiply
    289.09x = 431.06 × 278.56
  4. Step 4: Simplify right side
    289.09x = 120,076.07
  5. Step 5: Solve for x
    x = 120,076.07/289.09
  6. Step 6: Final answer
    x = 415.36

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.