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Finding the Fourth Proportional to 71.55, 98.72 and 40.45

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Solution

The fourth proportional to 71.55, 98.72 and 40.45 is: 55.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    71.55 : 98.72 = 40.45 : x
  2. Step 2: Convert to fraction form
    71.55/98.72 = 40.45/x
  3. Step 3: Cross multiply
    71.55x = 98.72 × 40.45
  4. Step 4: Simplify right side
    71.55x = 3,993.22
  5. Step 5: Solve for x
    x = 3,993.22/71.55
  6. Step 6: Final answer
    x = 55.81

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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.