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Finding the Fourth Proportional to 65.81, 90.28 and 64.10

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Solution

The fourth proportional to 65.81, 90.28 and 64.10 is: 87.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    65.81 : 90.28 = 64.10 : x
  2. Step 2: Convert to fraction form
    65.81/90.28 = 64.10/x
  3. Step 3: Cross multiply
    65.81x = 90.28 × 64.10
  4. Step 4: Simplify right side
    65.81x = 5,786.95
  5. Step 5: Solve for x
    x = 5,786.95/65.81
  6. Step 6: Final answer
    x = 87.93

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.