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Finding the Fourth Proportional to 123.66, 170.51 and 100.31

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Solution

The fourth proportional to 123.66, 170.51 and 100.31 is: 138.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    123.66 : 170.51 = 100.31 : x
  2. Step 2: Convert to fraction form
    123.66/170.51 = 100.31/x
  3. Step 3: Cross multiply
    123.66x = 170.51 × 100.31
  4. Step 4: Simplify right side
    123.66x = 17,102.50
  5. Step 5: Solve for x
    x = 17,102.50/123.66
  6. Step 6: Final answer
    x = 138.30

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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.