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Finding the Fourth Proportional to 71.65, 106.66 and 70.87

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Solution

The fourth proportional to 71.65, 106.66 and 70.87 is: 105.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    71.65 : 106.66 = 70.87 : x
  2. Step 2: Convert to fraction form
    71.65/106.66 = 70.87/x
  3. Step 3: Cross multiply
    71.65x = 106.66 × 70.87
  4. Step 4: Simplify right side
    71.65x = 7,558.99
  5. Step 5: Solve for x
    x = 7,558.99/71.65
  6. Step 6: Final answer
    x = 105.50

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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.