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Finding the Fourth Proportional to 66.80, 100.40 and 66.08

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Solution

The fourth proportional to 66.80, 100.40 and 66.08 is: 99.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    66.80 : 100.40 = 66.08 : x
  2. Step 2: Convert to fraction form
    66.80/100.40 = 66.08/x
  3. Step 3: Cross multiply
    66.80x = 100.40 × 66.08
  4. Step 4: Simplify right side
    66.80x = 6,634.43
  5. Step 5: Solve for x
    x = 6,634.43/66.80
  6. Step 6: Final answer
    x = 99.32

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.