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Finding the Fourth Proportional to 108.90, 162.50 and 90.90

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Solution

The fourth proportional to 108.90, 162.50 and 90.90 is: 135.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    108.90 : 162.50 = 90.90 : x
  2. Step 2: Convert to fraction form
    108.90/162.50 = 90.90/x
  3. Step 3: Cross multiply
    108.90x = 162.50 × 90.90
  4. Step 4: Simplify right side
    108.90x = 14,770.80
  5. Step 5: Solve for x
    x = 14,770.80/108.90
  6. Step 6: Final answer
    x = 135.64

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.