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Finding the Fourth Proportional to 65.79, 90.75 and 48.31

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Solution

The fourth proportional to 65.79, 90.75 and 48.31 is: 66.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    65.79 : 90.75 = 48.31 : x
  2. Step 2: Convert to fraction form
    65.79/90.75 = 48.31/x
  3. Step 3: Cross multiply
    65.79x = 90.75 × 48.31
  4. Step 4: Simplify right side
    65.79x = 4,384.09
  5. Step 5: Solve for x
    x = 4,384.09/65.79
  6. Step 6: Final answer
    x = 66.64

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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.