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Finding the Fourth Proportional to 71.40, 106.64 and 53.40

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Solution

The fourth proportional to 71.40, 106.64 and 53.40 is: 79.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    71.40 : 106.64 = 53.40 : x
  2. Step 2: Convert to fraction form
    71.40/106.64 = 53.40/x
  3. Step 3: Cross multiply
    71.40x = 106.64 × 53.40
  4. Step 4: Simplify right side
    71.40x = 5,694.58
  5. Step 5: Solve for x
    x = 5,694.58/71.40
  6. Step 6: Final answer
    x = 79.76

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.