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Finding the Fourth Proportional to 256.45, 353.63 and 209.67

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Solution

The fourth proportional to 256.45, 353.63 and 209.67 is: 289.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    256.45 : 353.63 = 209.67 : x
  2. Step 2: Convert to fraction form
    256.45/353.63 = 209.67/x
  3. Step 3: Cross multiply
    256.45x = 353.63 × 209.67
  4. Step 4: Simplify right side
    256.45x = 74,146.79
  5. Step 5: Solve for x
    x = 74,146.79/256.45
  6. Step 6: Final answer
    x = 289.13

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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.