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Finding the Fourth Proportional to 208.60, 287.80 and 159.40

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Solution

The fourth proportional to 208.60, 287.80 and 159.40 is: 219.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    208.60 : 287.80 = 159.40 : x
  2. Step 2: Convert to fraction form
    208.60/287.80 = 159.40/x
  3. Step 3: Cross multiply
    208.60x = 287.80 × 159.40
  4. Step 4: Simplify right side
    208.60x = 45,875.32
  5. Step 5: Solve for x
    x = 45,875.32/208.60
  6. Step 6: Final answer
    x = 219.92

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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.