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Finding the Fourth Proportional to 71.60, 99 and 65.45

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Solution

The fourth proportional to 71.60, 99 and 65.45 is: 90.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    71.60 : 99 = 65.45 : x
  2. Step 2: Convert to fraction form
    71.60/99 = 65.45/x
  3. Step 3: Cross multiply
    71.60x = 99 × 65.45
  4. Step 4: Simplify right side
    71.60x = 6,479.80
  5. Step 5: Solve for x
    x = 6,479.80/71.60
  6. Step 6: Final answer
    x = 90.50

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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.