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Finding the Fourth Proportional to 1.12, 1.55 and 0.72

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Solution

The fourth proportional to 1.12, 1.55 and 0.72 is: 0.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    1.12 : 1.55 = 0.72 : x
  2. Step 2: Convert to fraction form
    1.12/1.55 = 0.72/x
  3. Step 3: Cross multiply
    1.12x = 1.55 × 0.72
  4. Step 4: Simplify right side
    1.12x = 1.11
  5. Step 5: Solve for x
    x = 1.11/1.12
  6. Step 6: Final answer
    x = 0.99

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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.