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Finding the Fourth Proportional to 108.45, 149.69 and 64.80

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Solution

The fourth proportional to 108.45, 149.69 and 64.80 is: 89.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    108.45 : 149.69 = 64.80 : x
  2. Step 2: Convert to fraction form
    108.45/149.69 = 64.80/x
  3. Step 3: Cross multiply
    108.45x = 149.69 × 64.80
  4. Step 4: Simplify right side
    108.45x = 9,699.91
  5. Step 5: Solve for x
    x = 9,699.91/108.45
  6. Step 6: Final answer
    x = 89.44

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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.