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Finding the Fourth Proportional to 103.72, 143.14 and 90.76

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Solution

The fourth proportional to 103.72, 143.14 and 90.76 is: 125.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    103.72 : 143.14 = 90.76 : x
  2. Step 2: Convert to fraction form
    103.72/143.14 = 90.76/x
  3. Step 3: Cross multiply
    103.72x = 143.14 × 90.76
  4. Step 4: Simplify right side
    103.72x = 12,991.39
  5. Step 5: Solve for x
    x = 12,991.39/103.72
  6. Step 6: Final answer
    x = 125.25

Related Problems

Find fourth proportional to 51.86, 71.57 and 45.38
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Double scale
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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.