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Finding the Fourth Proportional to 66.19, 91.31 and 49.81

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Solution

The fourth proportional to 66.19, 91.31 and 49.81 is: 68.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    66.19 : 91.31 = 49.81 : x
  2. Step 2: Convert to fraction form
    66.19/91.31 = 49.81/x
  3. Step 3: Cross multiply
    66.19x = 91.31 × 49.81
  4. Step 4: Simplify right side
    66.19x = 4,547.67
  5. Step 5: Solve for x
    x = 4,547.67/66.19
  6. Step 6: Final answer
    x = 68.71

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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.