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Finding the Fourth Proportional to 111.79, 154.20 and 90.01

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Solution

The fourth proportional to 111.79, 154.20 and 90.01 is: 124.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    111.79 : 154.20 = 90.01 : x
  2. Step 2: Convert to fraction form
    111.79/154.20 = 90.01/x
  3. Step 3: Cross multiply
    111.79x = 154.20 × 90.01
  4. Step 4: Simplify right side
    111.79x = 13,879.54
  5. Step 5: Solve for x
    x = 13,879.54/111.79
  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.