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Finding the Fourth Proportional to 77.21, 106.53 and 65.60

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Solution

The fourth proportional to 77.21, 106.53 and 65.60 is: 90.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    77.21 : 106.53 = 65.60 : x
  2. Step 2: Convert to fraction form
    77.21/106.53 = 65.60/x
  3. Step 3: Cross multiply
    77.21x = 106.53 × 65.60
  4. Step 4: Simplify right side
    77.21x = 6,987.84
  5. Step 5: Solve for x
    x = 6,987.84/77.21
  6. Step 6: Final answer
    x = 90.51

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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.