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Finding the Fourth Proportional to 105.51, 145.62 and 66.20

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Solution

The fourth proportional to 105.51, 145.62 and 66.20 is: 91.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    105.51 : 145.62 = 66.20 : x
  2. Step 2: Convert to fraction form
    105.51/145.62 = 66.20/x
  3. Step 3: Cross multiply
    105.51x = 145.62 × 66.20
  4. Step 4: Simplify right side
    105.51x = 9,639.32
  5. Step 5: Solve for x
    x = 9,639.32/105.51
  6. Step 6: Final answer
    x = 91.36

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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.