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Finding the Fourth Proportional to 90.69, 135.56 and 70.18

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Solution

The fourth proportional to 90.69, 135.56 and 70.18 is: 104.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    90.69 : 135.56 = 70.18 : x
  2. Step 2: Convert to fraction form
    90.69/135.56 = 70.18/x
  3. Step 3: Cross multiply
    90.69x = 135.56 × 70.18
  4. Step 4: Simplify right side
    90.69x = 9,513.81
  5. Step 5: Solve for x
    x = 9,513.81/90.69
  6. Step 6: Final answer
    x = 104.91

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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.