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Finding the Fourth Proportional to 1,379.10, 2,065.90 and 646.45

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Solution

The fourth proportional to 1,379.10, 2,065.90 and 646.45 is: 968.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,379.10 : 2,065.90 = 646.45 : x
  2. Step 2: Convert to fraction form
    1,379.10/2,065.90 = 646.45/x
  3. Step 3: Cross multiply
    1,379.10x = 2,065.90 × 646.45
  4. Step 4: Simplify right side
    1,379.10x = 1,335,501.06
  5. Step 5: Solve for x
    x = 1,335,501.06/1,379.10
  6. Step 6: Final answer
    x = 968.39

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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.