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Finding the Fourth Proportional to 638.18, 880.38 and 389.51

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Solution

The fourth proportional to 638.18, 880.38 and 389.51 is: 537.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    638.18 : 880.38 = 389.51 : x
  2. Step 2: Convert to fraction form
    638.18/880.38 = 389.51/x
  3. Step 3: Cross multiply
    638.18x = 880.38 × 389.51
  4. Step 4: Simplify right side
    638.18x = 342,916.81
  5. Step 5: Solve for x
    x = 342,916.81/638.18
  6. Step 6: Final answer
    x = 537.34

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1.5x scale

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.