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Finding the Fourth Proportional to 65.68, 90.45 and 64.39

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Solution

The fourth proportional to 65.68, 90.45 and 64.39 is: 88.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    65.68 : 90.45 = 64.39 : x
  2. Step 2: Convert to fraction form
    65.68/90.45 = 64.39/x
  3. Step 3: Cross multiply
    65.68x = 90.45 × 64.39
  4. Step 4: Simplify right side
    65.68x = 5,824.08
  5. Step 5: Solve for x
    x = 5,824.08/65.68
  6. Step 6: Final answer
    x = 88.67

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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.