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Finding the Fourth Proportional to 200.40, 300.72 and 84.90

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Solution

The fourth proportional to 200.40, 300.72 and 84.90 is: 127.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    200.40 : 300.72 = 84.90 : x
  2. Step 2: Convert to fraction form
    200.40/300.72 = 84.90/x
  3. Step 3: Cross multiply
    200.40x = 300.72 × 84.90
  4. Step 4: Simplify right side
    200.40x = 25,531.13
  5. Step 5: Solve for x
    x = 25,531.13/200.40
  6. Step 6: Final answer
    x = 127.40

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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.