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Finding the Fourth Proportional to 124.90, 172.35 and 85.66

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Solution

The fourth proportional to 124.90, 172.35 and 85.66 is: 118.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    124.90 : 172.35 = 85.66 : x
  2. Step 2: Convert to fraction form
    124.90/172.35 = 85.66/x
  3. Step 3: Cross multiply
    124.90x = 172.35 × 85.66
  4. Step 4: Simplify right side
    124.90x = 14,763.07
  5. Step 5: Solve for x
    x = 14,763.07/124.90
  6. Step 6: Final answer
    x = 118.20

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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.