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Finding the Fourth Proportional to 292.20, 438.18 and 99.80

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Solution

The fourth proportional to 292.20, 438.18 and 99.80 is: 149.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    292.20 : 438.18 = 99.80 : x
  2. Step 2: Convert to fraction form
    292.20/438.18 = 99.80/x
  3. Step 3: Cross multiply
    292.20x = 438.18 × 99.80
  4. Step 4: Simplify right side
    292.20x = 43,730.36
  5. Step 5: Solve for x
    x = 43,730.36/292.20
  6. Step 6: Final answer
    x = 149.66

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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.