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Finding the Fourth Proportional to 89.99, 124.31 and 71.70

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Solution

The fourth proportional to 89.99, 124.31 and 71.70 is: 99.04

Step by Step Solution

  1. Step 1: Write the proportion equation
    89.99 : 124.31 = 71.70 : x
  2. Step 2: Convert to fraction form
    89.99/124.31 = 71.70/x
  3. Step 3: Cross multiply
    89.99x = 124.31 × 71.70
  4. Step 4: Simplify right side
    89.99x = 8,913.21
  5. Step 5: Solve for x
    x = 8,913.21/89.99
  6. Step 6: Final answer
    x = 99.04

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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.