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Finding the Fourth Proportional to 1,259.58, 1,890.51 and 643.71

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Solution

The fourth proportional to 1,259.58, 1,890.51 and 643.71 is: 966.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,259.58 : 1,890.51 = 643.71 : x
  2. Step 2: Convert to fraction form
    1,259.58/1,890.51 = 643.71/x
  3. Step 3: Cross multiply
    1,259.58x = 1,890.51 × 643.71
  4. Step 4: Simplify right side
    1,259.58x = 1,216,940.19
  5. Step 5: Solve for x
    x = 1,216,940.19/1,259.58
  6. Step 6: Final answer
    x = 966.15

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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.