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Finding the Fourth Proportional to 103.80, 143.22 and 99.60

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Solution

The fourth proportional to 103.80, 143.22 and 99.60 is: 137.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    103.80 : 143.22 = 99.60 : x
  2. Step 2: Convert to fraction form
    103.80/143.22 = 99.60/x
  3. Step 3: Cross multiply
    103.80x = 143.22 × 99.60
  4. Step 4: Simplify right side
    103.80x = 14,264.71
  5. Step 5: Solve for x
    x = 14,264.71/103.80
  6. Step 6: Final answer
    x = 137.42

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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.