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Finding the Fourth Proportional to 71.90, 98.94 and 65

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Solution

The fourth proportional to 71.90, 98.94 and 65 is: 89.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    71.90 : 98.94 = 65 : x
  2. Step 2: Convert to fraction form
    71.90/98.94 = 65/x
  3. Step 3: Cross multiply
    71.90x = 98.94 × 65
  4. Step 4: Simplify right side
    71.90x = 6,431.10
  5. Step 5: Solve for x
    x = 6,431.10/71.90
  6. Step 6: Final answer
    x = 89.45

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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.