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Finding the Fourth Proportional to 105.35, 145.31 and 65.45

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Solution

The fourth proportional to 105.35, 145.31 and 65.45 is: 90.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    105.35 : 145.31 = 65.45 : x
  2. Step 2: Convert to fraction form
    105.35/145.31 = 65.45/x
  3. Step 3: Cross multiply
    105.35x = 145.31 × 65.45
  4. Step 4: Simplify right side
    105.35x = 9,510.21
  5. Step 5: Solve for x
    x = 9,510.21/105.35
  6. Step 6: Final answer
    x = 90.28

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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.