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Finding the Fourth Proportional to 1,871.12, 2,806.45 and 638.65

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Solution

The fourth proportional to 1,871.12, 2,806.45 and 638.65 is: 957.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,871.12 : 2,806.45 = 638.65 : x
  2. Step 2: Convert to fraction form
    1,871.12/2,806.45 = 638.65/x
  3. Step 3: Cross multiply
    1,871.12x = 2,806.45 × 638.65
  4. Step 4: Simplify right side
    1,871.12x = 1,792,341.20
  5. Step 5: Solve for x
    x = 1,792,341.20/1,871.12
  6. Step 6: Final answer
    x = 957.90

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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.