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Finding the Fourth Proportional to 66.87, 99.87 and 53.30

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Solution

The fourth proportional to 66.87, 99.87 and 53.30 is: 79.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    66.87 : 99.87 = 53.30 : x
  2. Step 2: Convert to fraction form
    66.87/99.87 = 53.30/x
  3. Step 3: Cross multiply
    66.87x = 99.87 × 53.30
  4. Step 4: Simplify right side
    66.87x = 5,322.57
  5. Step 5: Solve for x
    x = 5,322.57/66.87
  6. Step 6: Final answer
    x = 79.60

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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.