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Finding the Fourth Proportional to 90.21, 124.51 and 70.77

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Solution

The fourth proportional to 90.21, 124.51 and 70.77 is: 97.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    90.21 : 124.51 = 70.77 : x
  2. Step 2: Convert to fraction form
    90.21/124.51 = 70.77/x
  3. Step 3: Cross multiply
    90.21x = 124.51 × 70.77
  4. Step 4: Simplify right side
    90.21x = 8,812.06
  5. Step 5: Solve for x
    x = 8,812.06/90.21
  6. Step 6: Final answer
    x = 97.68

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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.