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Finding the Fourth Proportional to 105.02, 145.07 and 72.21

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Solution

The fourth proportional to 105.02, 145.07 and 72.21 is: 99.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    105.02 : 145.07 = 72.21 : x
  2. Step 2: Convert to fraction form
    105.02/145.07 = 72.21/x
  3. Step 3: Cross multiply
    105.02x = 145.07 × 72.21
  4. Step 4: Simplify right side
    105.02x = 10,475.50
  5. Step 5: Solve for x
    x = 10,475.50/105.02
  6. Step 6: Final answer
    x = 99.75

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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.