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Finding the Fourth Proportional to 291.60, 402.40 and 208.64

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Solution

The fourth proportional to 291.60, 402.40 and 208.64 is: 287.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    291.60 : 402.40 = 208.64 : x
  2. Step 2: Convert to fraction form
    291.60/402.40 = 208.64/x
  3. Step 3: Cross multiply
    291.60x = 402.40 × 208.64
  4. Step 4: Simplify right side
    291.60x = 83,956.74
  5. Step 5: Solve for x
    x = 83,956.74/291.60
  6. Step 6: Final answer
    x = 287.92

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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.