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Finding the Fourth Proportional to 64.69, 89.28 and 38.81

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Solution

The fourth proportional to 64.69, 89.28 and 38.81 is: 53.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    64.69 : 89.28 = 38.81 : x
  2. Step 2: Convert to fraction form
    64.69/89.28 = 38.81/x
  3. Step 3: Cross multiply
    64.69x = 89.28 × 38.81
  4. Step 4: Simplify right side
    64.69x = 3,465.18
  5. Step 5: Solve for x
    x = 3,465.18/64.69
  6. Step 6: Final answer
    x = 53.57

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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.