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Finding the Fourth Proportional to 71.58, 98.84 and 64.74

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Solution

The fourth proportional to 71.58, 98.84 and 64.74 is: 89.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    71.58 : 98.84 = 64.74 : x
  2. Step 2: Convert to fraction form
    71.58/98.84 = 64.74/x
  3. Step 3: Cross multiply
    71.58x = 98.84 × 64.74
  4. Step 4: Simplify right side
    71.58x = 6,398.90
  5. Step 5: Solve for x
    x = 6,398.90/71.58
  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.