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Finding the Fourth Proportional to 71.50, 98.62 and 64.82

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Solution

The fourth proportional to 71.50, 98.62 and 64.82 is: 89.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    71.50 : 98.62 = 64.82 : x
  2. Step 2: Convert to fraction form
    71.50/98.62 = 64.82/x
  3. Step 3: Cross multiply
    71.50x = 98.62 × 64.82
  4. Step 4: Simplify right side
    71.50x = 6,392.08
  5. Step 5: Solve for x
    x = 6,392.08/71.50
  6. Step 6: Final answer
    x = 89.40

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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.