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Finding the Fourth Proportional to 102.55, 141.40 and 90.05

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Solution

The fourth proportional to 102.55, 141.40 and 90.05 is: 124.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    102.55 : 141.40 = 90.05 : x
  2. Step 2: Convert to fraction form
    102.55/141.40 = 90.05/x
  3. Step 3: Cross multiply
    102.55x = 141.40 × 90.05
  4. Step 4: Simplify right side
    102.55x = 12,733.07
  5. Step 5: Solve for x
    x = 12,733.07/102.55
  6. Step 6: Final answer
    x = 124.16

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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.