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Finding the Fourth Proportional to 687.65, 948.98 and 389.01

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Solution

The fourth proportional to 687.65, 948.98 and 389.01 is: 536.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    687.65 : 948.98 = 389.01 : x
  2. Step 2: Convert to fraction form
    687.65/948.98 = 389.01/x
  3. Step 3: Cross multiply
    687.65x = 948.98 × 389.01
  4. Step 4: Simplify right side
    687.65x = 369,160.76
  5. Step 5: Solve for x
    x = 369,160.76/687.65
  6. Step 6: Final answer
    x = 536.85

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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.