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Finding the Fourth Proportional to 101.79, 140.58 and 90.15

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Solution

The fourth proportional to 101.79, 140.58 and 90.15 is: 124.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    101.79 : 140.58 = 90.15 : x
  2. Step 2: Convert to fraction form
    101.79/140.58 = 90.15/x
  3. Step 3: Cross multiply
    101.79x = 140.58 × 90.15
  4. Step 4: Simplify right side
    101.79x = 12,673.29
  5. Step 5: Solve for x
    x = 12,673.29/101.79
  6. Step 6: Final answer
    x = 124.50

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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.