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Finding the Fourth Proportional to 125, 172.50 and 79

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Solution

The fourth proportional to 125, 172.50 and 79 is: 109.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    125 : 172.50 = 79 : x
  2. Step 2: Convert to fraction form
    125/172.50 = 79/x
  3. Step 3: Cross multiply
    125x = 172.50 × 79
  4. Step 4: Simplify right side
    125x = 13,627.50
  5. Step 5: Solve for x
    x = 13,627.50/125
  6. Step 6: Final answer
    x = 109.02

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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.