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Finding the Fourth Proportional to 74.40, 111.68 and 65.90

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Solution

The fourth proportional to 74.40, 111.68 and 65.90 is: 98.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    74.40 : 111.68 = 65.90 : x
  2. Step 2: Convert to fraction form
    74.40/111.68 = 65.90/x
  3. Step 3: Cross multiply
    74.40x = 111.68 × 65.90
  4. Step 4: Simplify right side
    74.40x = 7,358.82
  5. Step 5: Solve for x
    x = 7,358.82/74.40
  6. Step 6: Final answer
    x = 98.91

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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.