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Finding the Fourth Proportional to 1,378.11, 2,065.61 and 646.16

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Solution

The fourth proportional to 1,378.11, 2,065.61 and 646.16 is: 968.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,378.11 : 2,065.61 = 646.16 : x
  2. Step 2: Convert to fraction form
    1,378.11/2,065.61 = 646.16/x
  3. Step 3: Cross multiply
    1,378.11x = 2,065.61 × 646.16
  4. Step 4: Simplify right side
    1,378.11x = 1,334,705.84
  5. Step 5: Solve for x
    x = 1,334,705.84/1,378.11
  6. Step 6: Final answer
    x = 968.50

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.